Battery Technical Manual for Motorcycles/ATVs/Snowmobiles

The information contained in this manual is based on materials from GS Yuasa Corporation

and Yuasa Battery, Inc. in the USA.

1/46

Table of Contents

1. Role and Functions of Motorcycle Batteries

2. A Practical Understanding of Lead Acid Batteries

3. Battery Construction

4. Battery Components

5. Types of Motorcycle Batteries

6. Basic Battery Characteristics

7. Handling New Batteries

8. Handling and Storage Before Sales

9. Recharging Batteries

2/46

1. Role and Functions of Motorcycle Batteries

Motorcycles use lead acid batteries, which supply electricity to the ignition and lighting systems.

Unlike automobile drivers, motorcycle riders can start the engine by kick-starting the engine or

pushing the vehicle when the battery is discharged. However, if the battery is not working

properly, it may cause a bulb or fuse to blow. Therefore, it is important to understand how a

battery functions and follow the correct maintenance procedures to avoid these problems. Battery

functions and requirement loads are listed in the following table.

Battery Function Requirement Load

Supply electricity for starting

Small voltage drop

Supply high current

Power for continuous cranking

Starter motor

High torque High current

High revolution speed High voltage

Cranking time Constant power

Supply constant and stable electricity

while engine is running

Ignition system

Ignition High voltage

Supply electricity for lighting system

Maintain stable voltage supply

Supply electricity when the load

exceeds generator capacity

Electrical component

Lighting Stable voltage

Stable operation

Maintain stable voltage supply Absorb voltage fluctuations

Proper capacity

Backup for electrical load

1-1 Starting

Batteries must be able to supply high current and voltage to the starter motor when the starter

switch is operated. The power supplied must be sufficient for the starter motor to rotate with

enough torque to start the engine even on cold mornings.

1-2 Lighting

While a vehicle is being ridden, the battery directly provides a sufficient and stable electricity

supply to the lighting and signal components. The battery also stabilizes the electricity supply

and acts as a protective buffer in the case of a power surge.

1-3 Ignition

Whilst the engine is running, the spark plug ignites the air-fuel mixture in the combustion

chamber. To generate the spark at the spark plug, the ignition system requires a stable

electricity supply with enough voltage to induce high voltage in the ignition coil.

1-4 Charging

Electricity, which is generated by the vehicle, is controlled at a constant voltage by the rectifier

regulator and it is used to charge the battery. Because a malfunction may occur if the generated

electricity exceeds the proper charging value, the battery absorbs any electricity fluctuations to

maintain the correct voltage and protect electrical components.

3/46

2. A Practical Understanding of Lead Acid Batteries

* This chapter comes from the Yuasa Technical Manual, which is available on the Yuasa Battery,

Inc. home page.

Lead acid batteries are relatively simple in design. Dissimilar metal plates are immersed in an

electrolyte solution consisting of sulfuric acid and water. These are then insulated from each other

with a permeable, non-conductive material, which allows the transfer of ions. The transfer of ions

occurs during the discharge and recharge of the battery. Also occurring is the change in specific

gravity or density of the electrolyte. During the discharge period, sulfuric acid is drawn from the

electrolyte into the pores of the plates. This reduces the specific gravity of the electrolyte and

increases the concentration of water. During the recharge, this action is reversed and the sulfuric

acid is driven from the plates, back into the electrolyte, increasing the specific gravity.

During the discharge, lead sulfate is being formed on the battery plates. Although this is the

normal activity within the battery during discharge, a timely recharge is required to drive out the

sulfuric acid into the electrolyte. Without this recharge, the lead sulfate will continue to develop

and become difficult if not impossible to break down during recharge. Once this advanced

sulfation develops, permanent capacity loss or total failure of the battery is likely. Besides the

sulfation concerns, many other detrimental actions are taking place inside the battery while in a

discharged condition.

The corrosive effect on the lead plates and connections within the battery is greatly increased due

to the reduced specific gravity of the electrolyte. The corrosion of the plates will typically result in a

gradual reduction in performance followed by battery failure. The corrosion associated with the

inter cell connectors and the connecting welds will in many instances result in a sudden battery

failure. The corroded connector may have sufficient integrity to support low drain accessories

such as lights and instruments, but lack the necessary strength to provide the high discharge

current required to start the vehicle. This corrosive effect can also dissolve the lead into solution,

which in turn may compromise the plate insulators and result in micro shorts. Another condition

that frequently occurs in a discharged battery is freezing. In a deeply discharged battery, the

electrolyte has a reduced specific gravity and becomes a higher percentage of water than sulfuric

acid. During this condition, the battery may freeze at temperatures as high as 0˚C (32˚F). The

electrolyte in a fully charged battery will not freeze in temperatures down to around –50˚C (–65˚F).

Deep discharge can be created by a multitude of conditions, but the predominant reason is

neglect. During long periods of storage, the battery state of charge must be checked and

maintained per the battery manufacturer’s recommendations. Other conditions that can drain the

battery are inoperative or inadequate charging systems on vehicles, parasitic or key off drains,

loose or dirty terminal connections, etc. Although many of these conditions can be corrected,

often the problems you cannot correct may be overcome by a periodic charging schedule. You

can establish a routine by which you check and charge the customer’s battery or recommend

4/46

permanently attaching a backup charger while the vehicle is not in use.

When charging the customer’s battery, always refer to the instructions on both the battery and the

charger. While maintaining the customer’s battery at a full state of charge will insure optimum life,

overcharging may significantly reduce it. With a conventional type battery that offers access to the

cell compartments, the periodic addition of distilled water may be required. Water loss is normal in

these batteries through the process of electrolysis and evaporation. Low electrolyte levels that

expose the lead plates to the air will result in permanent damage to the battery. Maintain the

electrolyte levels above the minimum fill line on the battery and at or below the maximum line. A

sealed (Valve Regulated Lead Acid) battery should be maintained with the same care as a

conventional type battery with the exception of the addition of distilled water. Sealed VRLA

batteries have a predetermined quantity of electrolyte added at the factory or in the field using the

acid bottle specified for the battery. Once activated, the battery is permanently sealed and must

never be opened.

5/46

3. Battery Construction

Motorcycle batteries are divided into two types by construction. One is the normal vented lead

acid battery type and the other is the VRLA (Valve Regulated Lead Acid) battery type. The battery

size and shape are different for each type and the batteries are classified as follows.

3-1 Vented Lead Acid Battery

Small motorcycles use this type of battery. Batteries are comprised of multiple battery cells that

are connected in series. A single cell generates about 2 V of electricity. Accordingly, a 6 V

battery consists of 3 cells and a 12 V battery consists of 6 cells.

6/46

Electrolyte plug

Negative plate

Positive plate

Separator

Terminal

Exhaust elbow joint

3-2 VRLA (Valve Regulated Lead Acid) Battery

This type of battery is sometimes called a “sealed battery” or “MF (maintenance free) battery”.

Recently, however, battery manufacturers call these batteries “VRLA”, because this term

properly expresses the construction compared to other terms. The term “VRLA” is also written

on the battery case.

VRLA batteries were developed for the following reasons:

a) Demands for modern motorcycles are for vehicles that are lighter and smaller than

automobiles. As a result, the installation space for the battery is smaller and locations where

the battery can be installed are limited.

b) Off-road motorcycles operate under harsh conditions with significant movement. Therefore,

these motorcycles require batteries that do not spill electrolyte.

c) Scooters require a large helmet storage space. Therefore, the space for the battery is

reduced to accommodate this larger storage space.

d) During long storage periods, such as during the winter season, batteries need to have less

self-discharge.

For the above-mentioned reasons, VRLA batteries were developed and constructed as follows:

a) Due to the battery construction, no inspection of the electrolyte level and no refilling of the

distilled water are required. As a result, the battery does not have a refilling plug and is

completely sealed. This is why a VRLA battery is sometimes called a “sealed battery”.

b) A special separator holds the electrolyte itself; therefore, the electrolyte does not move in the

battery case.

c) A pressure regulator rubber valve (control valve) and safety valve with filter are used.

d) Recently developed VRLA batteries are approximately half the size of vented type batteries.

Some VRLA batteries are filled with electrolyte and charged at the factory.

7/46

Cover body (P.P.)

Negative plate

Special separator

Battery case

Positive plate

Safety valve with filter

Pressure regulator rubber valve(control valve)

Seal cap

Terminal (lead-calcium alloy)

4. Battery Components

4-1 Plate

The plate is made from a lead alloy grid and filled with an active material. The active material of

the positive plate is lead dioxide and it has a chocolate brown color. The active material of the

negative plate is sponge lead and has a lead gray color.

Vented type batteries use a lead-antimony alloy for the grid and VRLA type batteries and high-

performance batteries use a lead-calcium alloy. Batteries that use a lead-calcium alloy have less

self-discharge and a smaller decrease in the electrolyte.

4-2 Separator and Glass Mat

The board, which is inserted between the positive plate and negative plate, is called the

separator. The function of the separator is to prevent a short circuit between the plates. The

separator is made of a glass or synthetic fiber, which is highly resistant to acid, and has many

pores to facilitate an electrochemical reaction.

4-2-1 Separator for Vented Type Batteries

The separator is made of a porous synthetic fiber with good permeability for ions.

4-2-2 Glass Mat

The glass mat for vented type batteries is made from crossed glass fibers and it exerts

pressure on the positive plate. The pressure keeps the active material on the positive plate.

Because motorcycles are subject to more vibration than automobiles during operation, it is

necessary for the glass mat to exert more pressure to prevent deterioration of the plate.

4-2-3 Separator for VRLA Batteries

A special fine glass fiber separator is used, which holds the electrolyte itself. The separator

transports the oxygen gas from the positive plate to the negative plate.

8/46

Grid Positive plate Negative plate

4-3 Electrolyte

The electrolyte of the battery is dilute sulfuric acid and is a colorless clear liquid. It plays an

important role in charging and discharging. Generally, the standard specific gravity of electrolyte is

1.280 at 20˚C. The specific gravity of the electrolyte for VRLA batteries is 1.320 at 20˚C, which is

higher than the specific gravity for vented type batteries.

VRLA batteries require a precise amount of electrolyte to be held in the separator. If there is too

much electrolyte, it will overflow and if there is too little electrolyte, performance will decrease.

Therefore, the precise amount of electrolyte for each cell is contained in the bottle that comes with

new VRLA batteries. Always use the correct amount of electrolyte for each battery.

4-4 Case and Cover

The battery case and cover are made of polypropylene or ABS resin. The battery case is divided

into 3 cells for 6 V batteries and 6 cells for 12 V batteries.

Vented type batteries have a separate filling plug for each cell, but the gas exhaust system is

centralized.

VRLA batteries are sealed after being filled with electrolyte and they have no ventilation during

normal operation. However, if the internal pressure increases significantly, such as due to

overcharging, a rubber safety valve (regulator valve) opens to release the pressure. The safety

valve is equipped with a ceramic filter to prevent ignition of the vented gases due to an external

spark.

4-5 Terminal Types

4-5-1 Bolt and Nut Terminal

A bolt and nut are used to secure the motorcycle wire harness to the battery. Typically, the bolt

size is 5 mm or 6 mm and an additional bracket is sometimes used to accommodate alternate

tightening directions on some motorcycles.

4-5-2 Quick Fastener Terminal

A flat plate type terminal is used for small capacity batteries. The motorcycle wire harness has a

quick coupler.

4-5-3 Lead Wire Terminal

Small 6 V batteries have lead wires, which are used to connect to the wire harness. The positive

lead has a male terminal and the negative lead has a round female terminal.

To insure good conductivity, battery terminals should always be clean and tightened securely.

9/46

4-6 Exhaust Tube

When a battery is charging, oxygen gas and hydrogen gas are generated. To release these gases

from inside the battery, the battery has an internal central exhaust passage, which leads to the

exhaust elbow joint. Because these gases contain acid, they will corrode motorcycle parts.

Therefore, an exhaust tube is fitted onto the exhaust elbow joint and routed carefully so that the

gases will be vented at a location that will not damage the vehicle.

Never pinch or kink the exhaust tube that is used to release the gases. If the exhaust gases are

not released, high pressure will build up in the battery, possibly causing the battery case to deform

or even cause the case to rupture.

The exhaust tube has a slit in the battery end of the tube to release gases in case the exhaust

tube is pinched or kinked. If you use a new normal tube as a substitute for the exhaust tube, be

sure to keep same length then cut. Make a slit in the end of the tube that is connected to the

battery. Also, make sure that the length of the tube is sufficient to release the gases in a safe

location that will not damage the vehicle.

The exhaust elbow joint of a new vented type battery is plugged using a rubber plug. The rubber

plug prevents oxidization of the negative plates. Do not remove this plug until the battery will be

used.

After filling the battery with electrolyte and installing it onto the motorcycle, be sure to remove the

rubber plug and install the exhaust tube. If the rubber plug is accidentally left installed, pressure

will build up in the battery, possibly causing the battery case to deform or even cause the case to

rupture.

10/46

Slit

Exhaust tube routingDo not pinch or kink

Outlet position Never place near chain or frame parts

5. Types of Motorcycle Batteries

The battery model code is classified into 3 types. The naming for each type is different. The

naming is as follows.

5-1 Normal Motorcycle Battery

1 Indicates voltage

6 = 6 V 12 = 12 V

2 Indicates normal motorcycle battery

3 Indicates type of battery case (external dimensions)

4 Indicates terminal shape and position of exhaust elbow joint

5 Indicates terminal pattern if shape is different

5-2 High-Performance Motorcycle Battery

1 Indicates high-performance battery

2 Indicates type of battery case (external dimensions)

3 Indicates battery polarity

4 Indicates terminal shape and position of exhaust elbow

joint

5-3 VRLA Battery

1 Indicates VRLA battery

Codes YT, YTR, YTZ, and GT are used in addition to YTX

2 Indicates starting performance of normal battery that

corresponds to VRLA battery

A = Downsized

3 Indicates battery polarity

4 Indicates readiness type

11/46

12 N 9 - 4B - 1

1 2 3 4 5

YB 10 L - A2

1 2 3 4

YTX 7 L - BS

1 2 3 4

6. Basic Battery Characteristics

As already mentioned, motorcycle batteries are classified into 2 types: vented lead acid type and

VRLA type.

The characteristics of each battery are as follows.

6-1 Chemical Reaction of Battery

6-1-1 Vented Type Batteries

a) Electrochemical Reaction during Discharging

During discharging, accumulated chemical energy at the positive plate and negative plate is

converted into electric energy. Due to an electron transfer, both the lead dioxide of the positive

plate and the lead of the negative plate are converted into lead sulfate. During this

electrochemical reaction, water is generated, which dilutes the electrolyte. As a result, the

specific gravity of the electrolyte lowers. Therefore, the specific gravity of the electrolyte

indicates the battery condition. As the electrolyte is diluted by water during discharging, it may

freeze more easily than the electrolyte in a fully charged battery.

Formula 1: Electrochemical Reaction during Discharging

Pb : Lead SO42- : Sulfate Ion

PbO2 : Lead dioxide 2e- : Electrons

PbSO4 : Lead sulfate H+ : Hydrogen Ion

12/46

Lead dioxide → Lead sulfate

Lead Lead dioxide

LoadLight, Ignition

Separator

+–

+–

Negative platePositive plate

ElectrolyteSulfuric acid → Diluted by water

Lead → Lead sulfate

Lead sulfate

Lead sulfate

Lead sulfate

Lead sulfate

Positive plate: PbO2 + 4H+ + SO42- + 2e- PbSO4 + 2H2O

Negative plate: Pb + SO42- PbSO4 + 2e-

b) Electrochemical Reaction during Charging

During charging, electrical energy accumulates in the positive plate and negative plate as

chemical energy. The lead sulfate of the positive plate is converted back to lead dioxide and the

lead sulfate of the negative plate is converted back to lead. The sulfur that is released from the

positive plate and negative plate returns to the electrolyte.

Formula 2: Electrochemical Reaction during Charging

c) Electrochemical Reaction during Charging and Discharging

Formula 1 (electrochemical reaction during discharging) and formula 2 (electrochemical

reaction during charging) can be expressed as a single formula as follows.

13/46

Lead sulfate → Lead dioxide

LeadLead

dioxide

ChargerGenerator

Separator

+–

+–

Negative platePositive plate

ElectrolyteDilute sulfuric acid →

Former specific gravity electrolyte

Lead sulfate → Lead

Lead sulfate

Lead sulfate

Lead sulfate

Lead sulfate

Positive plate Electrolyte Negative plate Positive plate Electrolyte Negative plate

PbO2 2H2SO4 Pb+ + PbSO4 2H2O PbSO4+ +

Charged condition Discharged condition

PbO2 + 4H+ + SO42- + 2e-Positive plate: PbSO4 + 2H2O

Negative plate: PbSO4 + 2e- Pb + SO42-

d) Electrochemical Reaction at Terminal State during Charging

When the battery is fully charged, the active materials of the positive plate and negative plate

have almost fully been converted back lead dioxide and lead respectively. If charging continues,

the charging current will decompose the water in the electrolyte into its elements, hydrogen and

oxygen. These generated gases are vented into the atmosphere through the exhaust system of

the battery. During charging, the battery must be kept away from sparks and flames because

hydrogen is highly flammable.

If the electrolyte level decreases due to this electrochemical reaction during charging and if

water is not supplied during maintenance, the positive and negative plates will be exposed to

the air. If the positive and negative plates are exposed to the air, they will oxidize, forming lead

sulfate. The lead sulfate prevents the electrochemical reaction and reduces the battery

performance. In addition, a low electrolyte level also causes other problems. Concentrated

electrolyte causes corrosion of the plates. Therefore, to insure a long battery life, do not allow

the electrolyte to decrease to a low level.

Formula 3: Electrolysis of Water at Terminal State during Charging

Formula 4: Gas Generation by Electrolysis of Water

Although the gases are generated as indicated in the above formulas, they are not generated at the

same time. Oxygen is generated during the middle and at the end of the charging period while

hydrogen is generated during the final period.

14/46

LeadLead

dioxideCharger

Generator

Separator

+–

+–

Electrolyte

Hydrogen

Oxygen

Hydrogen

Oxygen

Exhaust elbow joint

Electrolysis of water: H2O 1/2 O2↑ + H2↑ (Electrolyte decrease) decrease)

Positive plate: H2O 1/2 O2 + 2H+ + 2e-

Negative plate: 2H+ + 2e- H2

6-1-2 VRLA Batteries

a) Construction and Electrochemical Reaction during Discharging

The electrochemical reaction in VRLA batteries is the same as in normal vented type

batteries. The difference is the battery construction. In VRLA batteries, the battery case is

sealed using the pressure regulator rubber valve (control valve) and flow of the electrolyte

is very low compared to that in vented type batteries. The electrolyte is impregnated into

the separator and the negative plate has a larger capacity to absorb oxygen from the

positive plate when the battery is close to fully charged.

15/46

Lead dioxide→ Lead sulfate

+-

+-

Negative plate

Positive plate

Lead→Lead sulfate Lead dioxideL

ead

LoadLight, Ignition

Electrolyte-impregnated separator

Pressure regulator rubber valve

(control valve)

Lead for absorbing

oxygen

Lead sulfate

Lead sulfate

Lead sulfate

Lead sulfate

b) Electrochemical Reaction during Charging

During charging of a VRLA battery, the lead sulfate of the positive plate is converted into lead

dioxide and the lead sulfate of the negative plate is converted into lead. This is the same as in

a vented type battery. However, the negative plate has a larger capacity to absorb oxygen,

which is generated at the positive plate.

The cycle is repeated at the negative plate. lead → lead sulfate + water → lead

Water is not decomposed by current. This is the reason that the water level does not decrease

and there is no need to supply water.

However, the lead capacity of the negative plate is limited and if the charging exceeds the

capacity, the negative plate will not be able to absorb the oxygen and the pressure will

increase. As a result, the pressure valve opens to release gas, which causes the electrolyte

level to decrease. Whenever charging a VRLA battery, overcharging must be avoided. To

prevent damage due to overcharging, VRLA batteries require a dedicated VRLA battery

charger.

To absorb oxygen from the positive plate, the construction of a VRLA battery is different from

that of a vented type battery and the components of the battery function differently.

1. Quick generated Gas (O2) Movement

Oxygen gas has to move quickly from the positive plate to the negative plate. Therefore,

electrolyte is completely impregnated into the special porous glass mat separator and

controlled so that there is no flow of electrolyte in the battery.

2. Sealing from Air

Air (O2) from the atmosphere must not contact the negative plate.

The pressure regulator rubber valve (control valve) is used to prevent the intake of air when

the pressure inside the battery is negative. However, the valve functions to release the

positive gas pressure when the battery is overcharged.

3. Less Self-Discharge

Self-discharge generates a small amount of water. The positive and negative grids are

made of lead-calcium alloy, not lead-antimony alloy. The lead-calcium alloy grid provides

less self-discharge.

16/46

c) Electrochemical Reaction during Charging and Discharging

The discharging and charging electrochemical reaction is the same as in vented type

batteries. The difference is that the negative plate absorbs oxygen from the positive plate

and produces water. The water returns to the separator and is not released from the

sealed battery case except during overcharging.

d) VRLA Battery Electrochemical Reaction

Oxygen is converted back into water at the negative plate.

cf. Gas generation is the same as in vented type batteries.

Although the gases are generated as indicated in the above formulas, they are not

generated at the same time. Oxygen is generated during the middle and at the end of the

17/46

Oxygen generated at positive plate

ElectrolyteNegative plate

1/2 O2Pb ++ PbSO4 H2O+H2SO4

Negative plate(partial

discharging)

Water generated at negative plate

Lead sulfate → Lead dioxide

+-

+-

Negative plate

Positive plate

Lead sulfate → Lead

Lead dioxide

Lead sulfate

Lead sulfate

Lead

Lead sulfate

Lead sulfate

ChargerGenerator

Electrolyte-impregnated separator

Pressure regulator rubber valve

(control valve)

Lead forabsorbing

oxygen

Lead

DischargingLead sulfate

+ Water

Lead

Water

1/2 oxygen

Positive plate: H2O 1/2 O2 + 2H+ + 2e-

Negative plate: 2H+ + 2e- H2

charging period while hydrogen is generated during the final period.

6-2 Relationship between Specific Gravity and Discharge Amount

6-2-1 Specific Gravity

The specific gravity is proportional to the charging state of the battery. Therefore, you can

measure the specific gravity to check the battery charge. However, the specific gravity does

not increase linearly during charging due to a dispersion delay. Therefore, the battery charge

cannot be checked by measuring the specific gravity during charging.

Relationship between Electrolyte Specific Gravity and Discharging Rate of Vented Type

Batteries

18/46

Go

od

Ne

ed c

har

gin

g

1.280

1.260

1.240

1.220

1.200

1.180

1.160

1.140

1.120

12.72 V

100% Charge 50% Discharge Fully Discharged

12.48 V

12.24 V

12.00 V

11.76 V

Open Circuit Voltage Specific Gravity

Discharging Ratio %

6-2-2 Open Circuit Voltage

Because the battery case is sealed, you cannot check the specific gravity of VRLA batteries.

Therefore, you have to check the open circuit voltage to check the battery charge.

Note: The relationship between the open circuit voltage and the charging state of VRLA

batteries is not the same as with vented type batteries.

Relationship between Open Circuit Voltage and Discharge Rate of VRLA Type Batteries

6-3 Open Circuit Voltage of VRLA Batteries after Filling with Electrolyte

Dry type VRLA batteries have to be filled with electrolyte before use. After the battery is filled with

electrolyte, the open circuit voltage will be 12.6–12.8 V even without charging. This is because

simply filling the battery with electrolyte will give the battery a charge of around 80%. In addition,

the concentration of the electrolyte near the plates temporarily decreases while the electrolyte is

being added. The electrolyte is not stable immediately after filling the battery; therefore, you must

wait more than 20 minutes before sealing the battery then installing the seal cap.

Following condition battery needs charging as instructed battery case.

a) Removed seal cap battery before filling electrolyte

b) Hard to start engine due to winter cold temperature and long stocked battery after

manufacturing.

Note: You cannot accurately check the battery during charging or immediately after charging has

finished. Wait around 30 minutes until the battery state has stabilized before checking the

specific gravity or voltage for both vented type batteries and VRLA batteries.

19/46

13.0 V

12.8 V

12.6 V

12.4 V

12.2 V

12.0 V

11.8 V

11.4 V

11.6 V

11.2 V

100% Charge 50% Discharge Fully DischargedG

oo

dN

eed

ch

arg

ing

Open Circuit Voltage

Discharging Ratio %

6-4 Open Circuit Voltage Changes after Charging is Finished

After charging, the battery voltage changes as shown in the following graph.

Wait around 30 minutes until the battery state has stabilized before checking.

6-5 Temperature Conversion Formula for Electrolyte

The specific gravity of electrolyte changes according to the temperature. If the temperature is

extremely high or low, you have to adjust the hydrometer reading. This is because the electrolyte

volume increases or decreases according to the temperature although the mass does not change.

Use the following formula to convert the specific gravity according to the temperature.

D20 = D t + 0.0007 (t-20)

D20: Specific gravity after conversion according to temperature

Dt : Measured specific gravity at temperature t*

t : electrolyte temperature when it is measured.

* Temperature in degrees Celsius

20/46

18.0 V

17.0 V

16.0 V

15.0 V

14.0 V

13.0 V

12.0 V

10.0 V

11.0 V

Terminal Voltage

0 10 3020 5040 60

Charging Stop Charging (Ambient Temperature: 25°C)

Elapsed Time (Minutes)

6-6 Final Discharge Voltage

When the battery is discharging at a constant current, the voltage drops gradually, then it drops

more quickly past a certain limit point. If the battery is discharged to 0 V, it cannot recover to its

former state even if it is recharged.

Therefore, to keep the battery in good condition, the voltage should not decrease to lower than

this minimum voltage.

This minimum voltage is called the “final discharge voltage”.

The discharging characteristic and final discharge voltage are shown in the following graph and

table.

Discharging Rate Final Discharge Voltage/Cell 12 V Battery

5–10 hours 1.75 V 10.5 V

1 hour 1.60 V 9.6 V

High-rate discharge 1.0 V 6.0 V

21/46

12.0 V

10.2 V

10.5 V

9.6 V

Discharging Characteristic Curve

10.8 V

12.6 V

11.4 V

15 100

Terminal V

oltage

(V)

Final Discharge Voltage

Discharging Time (Hours)

Final Discharge Voltage

6-7 Battery Capacity

6-7-1Motorcycle Batteries

The battery capacity means the amount of electricity that can be obtained from a battery. It is

expressed as a product of the discharge current in amperes (A) and the discharge time in hours

(h).

The actual capacity is measured as the number of hours required for a 100% charged battery to

reach the discharge final voltage using a constant discharge rate and it is expressed using the

following formula.

Discharging is an electrochemical reaction between the active materials of the electrodes and

sulfuric acid. If the discharging current is too large, the dispersion of the sulfuric acid cannot

match the discharging speed. As a result, the quantity of sulfuric acid decreases around the

electrodes and the voltage decreases much more than with a small discharge current. Therefore,

the battery capacity is small for a high-rate discharge.

A motorcycle’s battery capacity is expressed at a 10-hour discharge rate. For example, if 11.2 Ah

is indicated on the battery case, the battery can supply 11.2 A in the 10 hours.

The following graph shows the discharge characteristics according to the discharge rate.

In the case of an 11.2 Ah/10 hour battery, 0.1C equals 1.12 A and the blue line shows a discharge

characteristic of 1.12 A per hour. 1C equals 11.2 A per hour and the red line shows the discharge

characteristic. Therefore, in the case of 11.2 A, the battery is completely discharged within an hour

and the final discharge voltage is around 9.5 V or less.

22/46

Capacity (Ah) = Discharge current (A) x Discharging time to final discharge voltage (h)

(Ambient Temperature: 25°C)

12.0 V

9.0 V

8.0 V

Discharging Time (Hours)

10.0 V

13.0 V

11.0 V

1 5 100

Terminal V

oltage

(V)

10-hour discharge rate

C = 10-Hour Rate Capacity

0.1C0.2C

0.4C0.6C

1C

2C

Discharge Characteristics of a VRLA Battery

6-7-2 Automobile Batteries

Automobile batteries use different discharge capacity standards. One standard uses a discharge

rate, which is the same as motorcycles, but the time and current are different.

DIN: 20-hour discharge rate to reach final discharge voltage of 10.5 V

SAE: Reserve capacity (RC): Time to reach final discharge voltage of 10.5 V

RC is one of the indications for battery capacity.

Battery condition: Fully charged

Discharge current: 25 A current drain*

* A typical automobile consumes around 25 A under an average electrical load and

the vehicle can supply power to necessary electrical components using 10.5 V.

JIS: 5-hour discharge rate to reach final discharge voltage of 10.5 V

Another standard to test battery capacity is Cold Cranking Ampere (CCA). DIN, SAE, and JIS

used different methods for CCA. But recently it is unified and now EN=IEC=SAE=JIS

The details are as follows.

Battery condition: Fully charged

Temperature: –18°C

Under the above conditions, CCA is the amount of current the battery can supply for 30 seconds while

maintaining at least 7.2 V. 7.2 V is the minimum voltage required for the ignition system to operate and

the maximum cranking time is considered to be 30 seconds.

CCA means the starting ability of the engine using the battery capacity under cold conditions.

Therefore, the larger the CCA value, the higher the starting ability.

23/46

Battery capacity

6-7-3 Correspondence for EU regulation

From 2010 model, new battery will have EU standards indication.

EU battery capacity is indicated by 20HR rate compare to JIS 10HR rate.

Even battery is the same, indication is little different by discharging hours.

For example, YTZ12S capacity is 11Ah by 10 hours discharging and 11.6Ah by 20 hours

discharging.

Also CCA value is also following EU standards.

VRLA battery positive plate and negative is close compare to vented battery and CCA value (high

rate discharge ability) is higher than vented battery. Capacity is proportional to size of plate. So

CCA difference is smaller than capacity difference compare to VRLA battery and automobile

vented battery.

24/46

12.0 V

11.0 V

10.0 V

9.0 V

8.0 V

0 V

7.2 V

0

Fully charged battery–18°C7.2 V after 30 seconds

7.0 V

CCA Value (A)

EU standards CCA

JIS indication(Japanese industrial standards)

EU standards indication for capacity

6-8 Temperature and Battery Capacity

The battery capacity changes according to the electrolyte temperature. As a result, it is more difficult

to start an engine under cold conditions. The reason is that the battery cannot discharge due to the

low electrolyte temperature. In addition, the engine requires more cranking power under cold

conditions because the oil becomes more viscous, which creates higher resistance.

The motorcycle battery capacity is measured at 25°C using a 10-hour discharge rate.

The relationship between the temperature and the starting requirements is shown in the following

table.

Engine Starting Torque Battery Power Battery Fatigue

25°C 100% 100% 100%

0°C 160% 80% 200%

–18°C 250% 50% 500%

For vehicles, such as snowmobiles and ATVs, which are used and stored in very cold conditions,

the battery and engine require heating by an external power source. This is because the engine

requires a lot of power for cranking due to the large oil resistance and the starter motor needs

more electricity.

25/46

–10

120

110

100

90

80

70

50

60

40

Ca

pac

ity (%

)

–20 –0 10 20 30 40

Electrolyte Temperature

Freezing area

6-9 Electrolyte Freezing Point

During discharge, the specific gravity of the electrolyte decreases and the concentration of

water, which freezes at 0°C, increases. Accordingly, if the battery is discharged completely

and the electrolyte specific gravity is low, the electrolyte may freeze. This will seriously

damage the plates, separator, and battery case. If the battery will be stored under cold

conditions, the battery should be charged fully before storage.

26/46

6-10 Discharge

6-10-1 Self-Discharge

Battery electricity is consumed inside the battery over time regardless of whether the battery

is connected to any electrical components. This is called a battery self-discharge.

The battery electricity decreases day by day while the motorcycle is stocked and both vented

type batteries and VRLA batteries require periodic maintenance.

Some foreign metals (impurities), which exist in the battery, separate out on the plate and

create a local battery. Current flows from the foreign metal to part of the plate, which

consumes electricity. This phenomenon occurs more if the battery is filled with dirty water that

includes impurities.

In addition, self-discharge is higher for battery grids that contain antimony, such as those in

vented type batteries.

6-10-2 Amount of Self-Discharge

The amount of self-discharge is affected by several factors.

1. Time after Charging

The amount of self-discharge is large immediately after charging, then it decreases

proportionate to the elapsed time.

2. Temperature

Self-discharge is proportionate to the temperature. When the electrolyte temperature is

high, self-discharge increases. As a result, self-discharge increases during the summer

time and the battery discharges more quickly.

3. Polar Grid Material

VRLA batteries, which use a lead-calcium alloy grid, have less self-discharge than

vented type batteries, which use a lead-antimony alloy grid.

In general, a VRLA battery discharges 2.5–4% per month and a vented type battery

discharges 5–8% per month although this varies according to the actual state of the

battery.

27/46

Examples of Foreign MetalPlatinum (Pt)Gold (Au)Silver (Ag)Nickel (Ni) Copper (Cu)Antimony (Sb)

Foreign metal

Current

Negative plate

Local battery creation

The relationship between the storage time and the remaining capacity according to the

temperature is shown in the following graph.

Battery type: VRLA battery YT4L-BS

Vented type battery YBN4L-B

28/46

2

100

90

80

70

50

60

40

Re

ma

inin

g C

ap

acity (%

)

1 3 4 5 6 7

Storage Time (Months)

0

0°C

25°C

40°C

0°C

25°C

40°C

6-10-3 Dark Current (Current Drain)

Motorcycle electrical systems consume a small amount of electricity even when the main

switch is turned to the off position because the Immobilizer, clock, computer memory, and

other components require a constant supply of electricity to function properly. This is called

dark current or current drain.

In addition, if the customer installs additional electrical accessories onto the motorcycle, the

battery voltage will decrease even more and the battery will discharge quickly.

Therefore, if the motorcycle is stored for a long time, the battery requires periodic

maintenance regardless of whether it is a vented type battery or VRLA battery.

Example of Discharge by Dark Current

Dark current: 0.002 amperes

Storage time: 90 days

Battery capacity: 11.2 Ah

0.002 x 24 hours = 0.048 Ah

0.048 x 90 = 4.32 Ah

4.32 ÷ 11.2 = 0.385 x 100 = 38.5%

38.5% of the electricity is lost by the dark current in 90 days.

Checking the Dark Current

To check the dark current, a multimeter is required that can measure the current in

mmA units while the main switch is turned to the off position. Do not turn the main

switch to the on position.

If the main switch is turned to the on position, a large current will flow, which could

cause the fuse of the multimeter to blow.

29/46

Negative battery lead

MultimeterBattery

To wire harness

6-10-4 Total Discharge

When vehicle is stored, the battery discharges by self-discharge and the dark current.

The following examples show the amount of discharge during 3 months of storage.

Example of Vented Type Battery

Model: YBR125

Battery capacity: 5.0 Ah

Self-discharge at 25°C: 7% per month

Dark current: 0.001 A

Self-discharge: 5 Ah x 0.07 x 3 months = 1.05 Ah

Dark current: 0.001 A x 24 hours x 90 days = 2.16 Ah

Total discharge: 1.05 Ah + 2.16 Ah = 3.21 Ah

3.21 ÷ 5.0 = 0.628 x 100 = 62.8%

Example of VRLA Battery

Model: FZ1

Battery capacity: 11.2 Ah

Self-discharge at 25°C: 4% per month

Dark current: 0.002 A

Self-discharge: 11.2 Ah x 0.04 x 3 months = 1.34 Ah

Dark current: 0.002 A x 24 hours x 90 days = 4.32 Ah

Total discharge: 1.34 Ah + 4.32 Ah = 5.66 Ah

5.66 ÷ 11.2 = 0.505 x 100 = 50.5%

Battery discharges naturally day by day. Therefore, if the vehicle is stored for a long time, periodic

charging is necessary. Lead sulfate, which is created on the plates during discharging, will crystallize.

Once the lead sulfate crystallizes, it will be very difficult to remove from the surface of the plate and

battery performance will decrease.

Therefore, periodic charging is very important during long-term storage to insure long battery life.

30/46

6-11 Charging Methods and Characteristics

6-11-1 Charging Vented Type Batteries

When a discharged vented type battery is charged using a constant current, the standard

current is 10% of the battery capacity.

When the charging of a discharged battery using a constant current begins, the voltage and

specific gravity will initially increase at a slow rate. Once the battery voltage reaches around

14.1–14.4 V (2.35–2.4 V per cell), gassing starts. After the gassing starts, the voltage will

increase quickly.

At the end of the charging and past the gassing starting point, voltage increases quickly and

reaches the maximum voltage. Accordingly, once the gassing starts, the charging is nearly

complete.

31/46

18.0 V

17.0 V

16.0 V

15.0 V

14.0 V

13.0 V

12.0 V

11.0 V

Terminal Voltage

2 4 86 1210 14

Vented Type Battery Charging Characteristics

16

ElectrolyteSpecific Gravity

1.30

1.20

1.10 ElectrolyteTemperature

20

30

Gassing point

Charging Time (Hours)

6-11-2 Charging VRLA Batteries

When the charging begins, the battery voltage increases, which is the same as with a vented

type battery. However, when the gassing starts, the oxygen is absorbed by the negative plate,

which causes the voltage to be unstable. In addition, the amount of electrolyte that flows is low

compared to a vented type battery. Therefore, overcharging, which reduces the amount of

electrolyte, must be avoided. Once the electrolyte is lost, battery performance will be lost. Less

flowable electrolyte can lead to higher battery temperatures and cause increased self-discharge

and overcharging.

The charging current should be kept under 10% of the battery capacity and the voltage should

be kept under 15 V. The charging current when the battery is at a fully charged state should be

kept under 5% of the battery capacity.

If a VRLA battery is deeply discharged, it will be difficult to recover the battery capacity

compared to a vented type battery. Therefore, charging a deeply discharged VRLA battery

requires a higher voltage to break down the sulfation (lead sulfate) of the plates.

For the above-mentioned reasons, a VRLA battery needs a special charger for optimum

charging that controls the current and voltage as shown in the following graph.

32/46

Charging Time (Hours)

20 V

16 V

12 V

8 V

4 V

Terminal Voltage

(V)

2 4 86 1210 14

VRLA Battery Charging Characteristics by constant voltage charger

Charging Current

(A)

2.5

2.0

1.5

1.0

0.5

0

Charging current

7. Handling New Batteries

7-1 Removing Old batteries

1. Turn the main switch to the off position to stop the engine. Do not stop the engine by

disconnecting the negative lead. Otherwise, electrical components could be damaged and the

electrical system could malfunction.

2. Always disconnect the battery lead from the negative battery terminal to prevent short

circuits. Then, disconnect the positive lead.

3. Remove the exhaust tube from the exhaust elbow joint. Then, remove the battery.

4. If the terminals are corroded, clean them.

7-2 Preparing New Batteries

Always wear rubber gloves and protective eye wear when handling electrolyte.

1. There are many battery sizes and capacities. Therefore, choose the battery that is suitable for

the vehicle from the compatibility list.

2. Fill the battery with the correct electrolyte.

* Vented type batteries and VRLA batteries use electrolyte with a different specific gravity,

which must never be mixed.

Vented type battery electrolyte specific gravity: 1.280

VRLA battery electrolyte specific gravity: 1.320

Also, VRLA batteries require the correct amount of electrolyte to obtain their full performance.

Always use the electrolyte bottle that comes with the battery.

* If the battery is filled with electrolyte at the factory, it does not have to be refilled.

33/46

7-3 Activating Vented Type Batteries and Filling with Electrolyte

1. Remove the filling plugs and cap from the exhaust elbow joint.

* Never reinstall this cap onto the exhaust elbow joint. Otherwise, the battery could explode.

2. Prepare the electrolyte.

3. Place the battery on a level surface and fill it with electrolyte up to UPPER LEVEL indicated on

the battery.

4. Wait until the electrolyte level has stabilized. Once the level goes down, add electrolyte up to

UPPER LEVEL again.

5. Let the battery stand for 20–30 minutes after filling it with electrolyte. The electrolyte needs

time to disperse through the separator.

6. After the battery is filled with electrolyte, it is able to supply electricity. However, the battery is

only able to provide around 80% of its full capacity. After the battery is filled with electrolyte,

initial charging is recommended. Initial charging will insure a longer battery life.

Charge the battery for 2–3 hours at a current equivalent to 10% of its rated capacity, which is

indicated on the battery case.

* During charging, electrolyte may spill out of the open battery filling holes. Be sure to loosely

refit the filling plugs before charging the battery.

7. After the initial charging, if the electrolyte level has decreased, add electrolyte up to UPPER

LEVEL.

8. After the charging is complete, tighten the filling plugs firmly. However, do not over-tighten the

filling plugs.

9. Wash off any spilled electrolyte from the battery using plenty of water. Pay particular attention

that any electrolyte is washed off of the terminals. Then, dry the battery completely.

34/46

UPPER LEVEL

LOWER LEVEL

Electrolyte 5–30C

Remove cap

7-4 Activating VRLA Batteries and Filling with Electrolyte

When activating the battery, check the following points:

* Always use the electrolyte bottle that is packed with the new battery. VRLA batteries need

electrolyte with a different specific gravity than that for vented type batteries. In addition,

VRLA batteries require an accurate volume of electrolyte for each cell.

* Do not remove the foil sheet covering the filling holes before activation.

1. Place the battery on a level surface and remove the foil sheet completely.

2. Keep the electrolyte bottle at a temperature of 5 - 30C.

3. Remove the strip cap from the electrolyte bottle. Place the strip cap aside—you will use this

strip cap as the sealing plug of the electrolyte filling holes of the battery.

* Do not open or break the seals of the electrolyte bottle.

4. Place the electrolyte bottle, with the sealed tops of the cells down, into the filling holes of the

battery. Hold the bottle level and push down to break the seals. After the seals have broken,

air bubbles will appear in the electrolyte as the electrolyte flows into each cell.

Do not tilt the electrolyte bottle.

35/46

5. To confirm that the electrolyte is flowing into the cells, check that bubbles have appeared in

the electrolyte or that the level of the electrolyte in the bottle goes down gradually. If bubbles

do not appear, lightly tap the affected bottle cells with your finger.

6. Let the battery stand for more than 20 minutes to 1 hour under the above condition.

7. After checking that all of the bottle cells are completely empty or that you cannot see any

electrolyte in the bottle, remove the electrolyte bottle from the battery and wipe off any spilled

electrolyte.

8. After filling the battery with electrolyte, wait 20–60 minutes, and then equally and firmly install

the strip cap with both hands. Do not pound the strip cap or use a hammer.

9. After electrolyte has been added, a new VRLA battery is approximately 80% charged and the

battery voltage is around 12.5–12.6 V.

After filling electrolyte and battery voltage is under 12.4V, recharge battery.

10. Charge the battery using a VRLA battery charger.

11. Following condition battery needs charging as instructed battery case.

a) Removed seal cap battery before filling electrolyte

b) Hard to start engine due to winter cold temperature and long stocked battery after

Handling Points for New Batteries

1. After activation, a new battery is approximately 80% charged.

2. An initial charge is recommended for vented battery. Never quick charge the battery.

3. Charge a new vented battery at a rate of 10% of its rated capacity.

4. The battery temperature must not exceed 50C.

36/46

8. Handling and Storage before Sales

8-1 Checking before Storage

After receiving a new battery from the supplier, check its condition before storage.

1. Check for any packing damage or leaking of electrolyte.

2. For vented type batteries, check that the filling plugs and exhaust tube are securely fitted.

3. For VRLA batteries, check that the proper electrolyte bottle is attached.

4. For VRLA batteries filled with electrolyte at the factory, check the open circuit voltage and

recharge the battery if the voltage is below 12.4 V.

8-2 Storage

1. Choose a cool place (–5 to 15C).

2. Keep the battery out of direct sunlight and do not store the battery in wet or very humid locations.

3. Avoid long-term storage as much as possible and use proper stock management to sell longer

stocked batteries first.

8-3 Recharging during Storage

1. Recharge the battery if 6 months has passed since the battery was manufactured.

2. Recharging every month is recommended for batteries in stock.

3. Recharge batteries using the suitable charging method.

9. Recharging Batteries

A battery must be recharged immediately if it is discharged by overuse or from being stored for a

long time.

If the battery is left with low voltage or in a discharged condition, it may lead to sulfation of the

plates and freezing of the electrolyte at low temperatures.

Battery recharging is required under the following conditions:

Vented type battery: Specific gravity is lower than 1.240

VRLA battery: Open circuit voltage is lower than 12.4 V

9-1 Battery Charger

Use a battery charger that is suitable for the small-capacity batteries for motorcycles, ATVs, and

snowmobiles.

To prevent overcharging, an automobile battery charger is not recommended.

VRLA batteries need a dedicated VRLA battery charger. Otherwise, the battery could be

overcharged, which could cause a decrease in the electrolyte level, reducing the battery

performance.

If you do not use a proper battery charger, you cannot expect a full charge and the battery could

be damaged.

37/46

9-2 Connecting the Battery and Battery Charger

1. Remove the battery from the vehicle. Do not charge the battery while it is still installed on

the vehicle.

2. Remove the battery charger plug from the power outlet to prevent sparking when the

battery charger leads are connected to the battery terminals.

3. When connecting the battery charger leads to the battery, make sure to connect the

positive and negative leads to the correct terminals. Never reverse the lead connections.

Otherwise, the electrical components of the vehicle and the battery could be damaged.

4. Do not connect 2 or more batteries in parallel for charging. It disarranges the charging

current.

9-3 Charging Current and Time

Different ampere-hour batteries have a different charge rate. For most motorcycle batteries,

charge them at 10% of the rated ampere-hour value, which is indicated on the battery case.

For quick charges, also follow the value indicated on the battery.

Always check the ampere-hour value of the battery and do not overcharge or over quick charge a

battery.

For Yamaha batteries, see the charts in the Appendix for the charging currents.

9-4 Estimated Charging Times

Open Circuit Voltage Estimated Charging Time

12.4 V Within 4 hours

12.3 V Within 6 hours

12.2 V Within 8 hours

12.1 V Within 10 hours

12.0 V Within 12 hours

11.8 V Within 15–20 hours

9-5 Precautions for Charging

1. During charging, the battery temperature will increase. Always keep the battery temperature

under 50C.

2. Charging generates hydrogen gas, which is highly flammable. Do not disconnect the battery

charger leads during charging. Otherwise, a spark may be produced.

Also, keep any fire or flame away from the battery during charging.

Charging Precautions for Vented Type Batteries

1. Remove the filling plugs and exhaust elbow joint cap.

2. Choose a well-ventilated place so that hydrogen gas does not collect.

3. Once the battery starts gassing, charging is almost finished.

4. Check the specific gravity of the electrolyte. When the specific gravity is over 1.270, charging is

completed.

5. After finishing charging, disconnect the battery charger plug from the power outlet.

6. Disconnect the battery charger leads from the battery terminals.

38/46

7. Tighten the filling plugs and wash off any electrolyte from the battery using plenty of water.

　Charging Precautions for VRLA Batteries

1. Never remove the sealing strip cap.

2. Use a VRLA battery charger.

3. When using a normal battery charger, charge the battery using the current and time indicated

on the battery case. If the battery temperature rises quickly, stop charging immediately.

4. Always keep the battery temperature under 50C.

9-6 Finishing Charging

Vented type batteries

Gassing starts and the specific gravity is 1.270–1.290.

VRLA batteries

Open circuit voltage is over 12.8 V.

9-7 Measuring the Specific Gravity Using a Hydrometer

9-8 Installing the Batteries

1. Make sure that the positions of the positive and negative terminals are the same as the

terminal positions of the removed battery.

2. Hold the battery securely and place it in the battery box.

3. Install the battery holder and tighten the fasteners.

4. First, connect the positive lead.

5. Next, connect the negative lead.

6. Apply a small amount of grease to the terminals to prevent rust.

7. Install the terminal covers.

8. Install the exhaust tube. Make sure that there are no kinks in the tube and that the end of

the tube is located in the correct location.

39/46

9-9 Check Points for Installation

40/46

Electrolyte level is OK

Terminal is clean

Exterior is clean and dry

Battery holder is securely tightened

Exhaust tube is securely fitted to exhaust elbow jointNo kinks or clogsRouting is OKTube end is located in correct location

Connect positive lead first

+

-

Appendix

Battery type Battery model Normal charging

current

Quick charging

current　

VRLA

Battery

GT4B-5 12V 2.5Ah WET 0.25Ax5~10 Hours No Quick charge V50 V50D V50N 　

　 　 　 　 YJ50R YV50H 　 　

YT4B-BS 12V 2.5Ah WET 0.3Ax8~10 Hours 3.0Ax0.5 RZ50 YB1-4 YB50 　

　 　 　 　 SR400 TT-R50 　 　

GT4L-BS12V 3.2Ah Dry

0.4Ax5~10 Hours 4.0Ax0.5 BA50 TT-R125 　 　

　 　 　 　 T90T T90D T90N 　

YT4L-BS 12V 3Ah Dry 0.4Ax5~10 Hours 4.0Ax0.5 　 　 　 　

　 　 　 　 　 　 　 　

YTZ5S 12V 3.5Ah Dry 0.4Ax5~10 Hours 3.0Ax0.5 　 　 　 　

　 　 　 　 　 　 　

YTX5L-BS 12V 4Ah Dry 0.5Ax5~10 Hours 5.0Ax0.5 　 　 　 　

　 　 　 　 　 　 　 　

GT6B-3 12V 6.0Ah WET 0.6Ax5~10 Hours No Quick charge XT225 XVS250 　 　

　 　 　 　 　 　 　

YTZ7S 12V 6.0Ah WET 0.6Ax5~10 Hours 3.0Ax1.0 AG200 XT225 XVS250 TW125

　 　 　 　 DT125 　 　 　

YTX7L-BS 12V 6.0Ah WET 0.7Ax5~10 Hours 3.0Ax1.0 YS250 YBR250 XTZ250 　

　 　 　 　 　 　 　 　

GT7B-412V 6.5Ah WET

0.65Ax5~10 Hours No Quick charge YFZ450 　 　 　

　 　 　 　 　 　 　 　

YT7B-BS 12V 6.5Ah DRY 0.7Ax5~10 Hours 3.0Ax1.0 YP250 TT250 TT-R250 YFZ450

　 　 　 　 　 　 　 　

GT9B-412V 8.0Ah WET

0.8Ax5~10 Hours No Quick charge YP250 YP250G YP400L 　

　 　 　 　 YP400 YP400G 　 　

　 　 　 　 XP500 　 　 　

　 　 　 　 XT660 MT03 YZF-R6 　

　 　 　 　 YFM700R 　 　 　

YTX9-BS 12V 8.0Ah Dry 0.9Ax5~10 Hours 4.0Ax1.0 XJR400 　 　 　

　 　 　 　 　 　 　 　

YTX9B-BS 12V 8.0Ah 0.9Ax5~10 Hours 4.0Ax1.0 　 　 　 　

　 　 　 　 　 　 　 　

YTZ10S 12V 8.6Ah WET 0.9Ax5~10 Hours 4.5Ax1.0 YZF-R1 YZF-R6 　 　

　 　 　 　 　 　 　

GT12B-412V 10.0Ah WET 1.0Ax5~10 Hours No Quick charge XVS400 　 　 　

41/46

　 　 　 　 　 　 　 　

YT12B-BS 12V 10.0Ah DRY 1.0Ax5~10 Hours 5.0Ax1.0 FZ6-N TDM900 XVS650 　

　 　 　 　 　 　 　 　

YTZ12S 12V 11.0Ah WET 1.1Ax5~10 Hours 5.5Ax1.0 　 　 　 　

　 　 　 　 　 　 　 　

YTX12-BS 12V 10.0Ah DRY 1.2Ax5~10 Hours 5.0Ax1.0 TRX 　 　 　

　 　 　 　 　 　 　 　

YTZ14S 12V 11.2Ah WET 1.1Ax5~10 Hours 5.5Ax1.0 FZ1 　 　 　

　 　 　 　 　 　 　 　

GT14B-412V 12.0Ah WET

1.2Ax5~10 Hours No Quick charge XJR1300 XVS1100 　 　

　 　 　 　 　 　 　 　

YTX14BS 12V 12Ah DRY 1.4Ax5~10 Hours　 　 XV1700 FJR1300 XJR1300 MT01

　 　 　 　 FZS1000 　 　 　

YTX20L-BS 12V 18.0Ah DRY 1.8Ax5~10 Hours 9.0Ax1.0 YFM700FW 　 　 　

　 　 　 　 　 　 　 　

　 U1L-11 12V 28.0Ah 　 　 YXR700 　 　 　

　 　 　 　 　 　 　 　 　

Battery type Battery model Normal charging

current

Quick charging

current　

Vented

battery6N4-2A-2

6V 4.0Ah0.4Ax15~20 Hours 　 RX135 AG100 YB100 YB50

　 　 　 　 　 　 　 　

6N4-2A-9 6V 4.0Ah 0.4Ax15~210 Hours 　 V80 　 　 　

　 　 　 　 　 　 　 　

6N4B-2A-3 6V 4.5Ah 0.4Ax15~20 Hours 　 AG200 　 　 　

　 　 　 　 　 　 　 　

6N6-3B-16V 6.0Ah

0.6Ax15~20 Hours 　 DT175 DT125 　 　

　　 　 　 　 　 　 　

12N7D-3B 12V 7.0Ah 0.7Ax15~20 Hours 　 YFM80 YFM50 　 　

　 　 　 　 　 　 　 　

12N12A-4A-112V 12.0Ah

1.2Ax15~210 Hours 　 SR250 　 　 　

　 　 　 　 　 　 　 　

12N12C-4A-2 12V 12.0Ah 1.2Ax15~210 Hours 　 YFM125 　 　 　

　 　 　 　 　 　 　 　

42/46

　 　 　 　 　 　 　 　

GM2.5A-3C 12V 2.5Ah 0.3Ax15~20 Hours 　 V50 　 　 　

　 　 　 　 　 　 　

YB2.5L-C-3 12V 2.5Ah 0.3Ax15~210 Hours 　 V50 　 　 　

　 　 　 　 　 　 　 　

GM3-3A12V 3.0Ah

0.3Ax15~20 Hours 　 DT50 　 　 　

　 　 　 　 　 　 　 　

YB3L-Ａ 12V 3.0Ah 0.3Ax15~20 Hours 　 DT50 　 　 　

　 　 　 　 　 　 　

GM3-3B12V 3.0Ah

0.3Ax15~210 Hours 　 DT175 DT125 　 　

　 　 　 　 　 　 　

YB3L-B 12V 3.0Ah 0.3Ax15~20 Hours 　 DT175 DT125 　 　

　 　 　 　 　 　 　

GM7CZ-3D 12V 7.0Ah 0.7Ax15~20 Hours 　 TW225 　 　 　

　 　 　 　 　 　 　 　

YB7C-A 12V 7.0Ah 0.7Ax15~20 Hours 　 TW200 　 　 　

　 　 　 　 　 　 　 　

GM10-3A-2 12V 10.0Ah 1.0Ax15~210 Hours 　 XV250 　 　 　

　 　 　 　 　 　 　 　

YB10L-A 12V 10.0Ah 1.0Ax15~20 Hours 　 XV250 　 　 　

　 　 　 　 　 　 　 　

GM12AZ-3A-212V 12.0Ah

1.2Ax15~210 Hours 　 FZR600 XV535 　 　

　 　 　 　 　 　 　 　

YB12AL-A2 12V 12.0Ah 1.2Ax15~20 Hours 　 FZR600 XV535 　 　

　 　 　 　 　 　 　 　

GM12CZ-4A-2 12V 12.0Ah 1.2Ax15~210 Hours 　 YFM350 　 　 　

　 　 　 　 　 　 　 　

YB12C-A 　12V 12.0Ah 1.2Ax15~20 Hours 　 YFM350 　 　 　

　 　 　 　 　 　 　 　

GM18Z-3A 12V 20.0Ah 2.0Ax15~20 Hours 　 SXV70 SXV60 　

　 　 　 　 　 　 　 　

Y50N18L-A 12V 20.0Ah 2.0Ax15~20 Hours 　 SXV70 SXV60 　 　

　 　 　 　 　 　 　 　

43/46

Battery interchangeability table

* This table information is based on GS-YUASA home page.

Include other manufacturer motorcycle battery

VRLA battery

Yuasa corp. GS battery Furukawa batteryGS-Yuasa battery

DRY WET(CHARGED)

YT-4B-BS GT4B-5 FT4B-5 YT4B-BS -

YT-4B-BS GT4B-5 FT4B-5 - GT4B-5

YT-4L BS/YTZ3 GT4L-BS FT4L-BS YT4L-BS YT4L-BS

YTX-5L-BS GTX5L-BS FTX5L-BS YTX-5L-BS YTX-5L-BS

YT7B-BS GT7B-4 FT7B-4 YT7B-BS -

YT7B-BS GT7B-4 FT7B-4 - GT7B-4

YTX7L-BS GTX7L-BS - YTX7L-BS YTX7L-BS

YTX9-BS/YTR9-BS GTX9-BS FTX9-BS YTX9-BS YTX9-BS

- GT9B FT9B - GT9B

YTX12-BS GTX12-BS FTX12-BS YTX12-BS YTX12-BS

YT12-BS - FT12A-BS YT12A-BS YT12A-BS

YTX14-BS - FTX14-BS YTX14-BS YTX14-BS

- GT14B-4 - - GT14B-4

YTX20L-BS - - YTX20L-BS YTX20L-BS

YTZ7S - FTZ5L-BS - YTZ7S

YTZ10S - - - YTZ10S

YTZ12S - - - YTZ12S

YTZ14S - - - YTZ14S

44/46

Vented battery

Yuasa corp. GS battery Furukawa batteryGS-Yuasa battery

DRY WET(CHARGED)

- 6N2-2A - - 6N2-2A

- 6N2-2A-4 - - 6N2-2A-4

- 6N2-2A-7 - - 6N2-2A-7

- 6N2-2A-8 - - 6N2-2A-8

- 6N2-2A-9 - - 6N2-2A-9

- 6N2A-2C - - 6N2A-2C

- 6N2A-2C-3 - - 6N2A-2C-3

- 6N2A-2C-4 - - 6N2A-2C-4

- 6N4-2A - - 6N4-2A

- 6N4-2A-2 - - 6N4-2A-2

- 6N4-2A-4 - - 6N4-2A-4

- 6N4-2A-7 - - 6N4-2A-7

- 6N4-2A-8 - - 6N4-2A-8

- 6N4-2A-9 - - 6N4-2A-9

- 6N4A-4D - - 6N4A-4D

- 6N4B-2A - - 6N4B-2A

- 6N4B-2A-3 - - 6N4B-2A-3

- 6N5.5-1D - - 6N5.5-1D

- 6N6-1D-2 - - 6N6-1D-2

- 6N6-3B - - 6N6-3B

- 6N6-3B-1 - - 6N6-3B-1

6YB8L 6GM8-3B 6FB8L-B 6BX8-3B 6YB8L-B

6N11A-3A - - - 6N11A-3A

45/46

6N11-2D 6GM11-2D - - 6YB11-2D

6N12A-2C - - - 6N12A-2C

6N12A-2D - - - 6N12A-2D

YB2.5L-C GM2.5A-3C-2 FB2.5L-C - YB2.5L-C

- GM2.5A-3C - - YB2.5L-C-3

YB3L-A GM3-3A FB3L-A - YB3L-A

YB3L-B GM3-3B FB3L-B - YB3L-B

YB4L-B GM4-3B FB-4L-B BX4A-3B YB4L-B

YB5L-B/12N5-3B GM5Z-3B FB5L-B - YB5L-B

12N5.5-3B 12N5.5-3B 12N5.5-3B - 12N5.5-3B

12N5.5-4A - - - 12N5.5-4A

12V5.5A-3B - - - 12V5.5A-3B

- GM6-4B - - YB6-B

- 12N7D-3B - - 12N7D-3B

YB7-A,12N7-4A GM7Z-4A FB7-A - YB7A

12N7B-3A - - - YB7LA

- GM7CZ-3D - - YB7C-A

12N7-3B GM7-3B-1 FB7L-B - YB7L-B

YB9-B,12N9-4B-1 FB9Z-4B FB9-B BX9-4B YB9-B

- GM9Z-3A-1 FB9L-A2 - YB9L-A2

YB9L-B GMZ9Z-3B FB9L-B - YB9L-B

- GM10-3A-2 - - YB10L-A

YB10L-A2 GM10Z-3A FB10L-A2 BX10-3A YB10L-A2

YB10L-B,12N10-3B GM10-3B FB10LA-B - YB10L-B

YB10L-B2 GM10Z-3B-2 FB10L-B2 - YB10L-B2

YB12A-A GM12AZ-4A-1 FB12A-A BX12A-4A YB12A-A

YB12A-AK GM12AZ-4A-1(s) FB12A-A(with sensor) - YB12A-AK

YB12A-B - - - YB12A-B

- GM12AZ-4B-2 - - YB12A-B2

YB12AL-A2 GM12AZ-3A-2 FB12AL-A - YB12AL-A2

YB12B-B2 GM12B-4B - - YB12B-B2

- GM12CZ-4A-2 - - YB12C-A

YB14-A2 GM14Z-4A FB14-A2 - YB14-A2

YB14-B2 GM14Z-4B - - YB14-B2

- GM14AZ-4A-1 - - YB14A-A2

YB14L-A1 - - - YB14L-A1

YB14L-A2 GM14Z-3A FB14L-A2 BX14-3A YB14L-A2

YB14L-B2 GM14Z-3B FB14L-B2 - YB14L-B2

SYB14L-A2 GM14Z-3A - - SYB14L-A2

46/46

YB16AL-A2 GM16A-3A - - YB16AL-A2

YB16-B GM16Z-4B FB16-B - UB16-B

YB16B-A GM16B-4A - - YB16B-A

YB16B-A1 - - - YB16B-A1

YB16CL-B GB16CL-B FB16CL-B - YB16CL-B

YB16HL-A-CX YB16HL-A-CX FB16L(12N16-3B) - YB16L-B

HYB16A-AB - - - HYB16A-AB

YB18L-A GM18A-3A - - YB18L-A

47/46