Battery Service Manual

1. Safety Precautions

Batteries are dangerous to handle or work on. They are filled with dilute sulfuric acid. If the electrolyte comes into contact with your skin or cloth,
flush it with enough amount of clean water and take medical care immediately.

Never bring cigarettes, flames or sparks near the battery. It may produce explosive hydrogen and oxygen gas when charging.

Keep batteries clean so that the venting holes are free from clogging materials. A clogged up battery
will have a high internal pressure which may crack the container or leak the electrolyte out of sealed portion.

Battery should not be kept in a confined space. In particular, when charging, please proceed in a well- ventilated place.

Please refrain from dismantling a battery since it is too dangerous.

This battery is designed and manufactured in accordance with conditions of vehicle operations. Please note that the described performance
of battery cannot be obtained when the battery is used for other equipment.

Safety Labeling ;

Each battery is marked with six kinds of symbols as follows. The meaning of each symbol is:







2. Battery Stock Maintenance

Always rotate your stock. Practice First In, First Out. Batteries are slowly discharged, good stock-rotation stops batteries going off during the storage and
makes sure that customers buy good batteries. Store batteries in a cool, dry, well-ventilated area.
The recommendable temperature of storage is 10~25°C. Protect batteries from excessive heat. (Heat causes batteries to lose capacity more quickly,
and excessive heat can damage batteries).Store batteries in an upright position. (To prevent them from falling or leaking).

Never stack batteries directly on the top of each other unless they are in boxes. In case of packing batteries, four-layer loading is recommended at the highest.
Store batteries on racks or on pallets, not on the floor. (Small stones or sharp points on concrete floor can damage the base of battery and cause leakage).

How to check a battery

Check the following points for safety and long life use.


Measure the open-circuit voltage of the battery using a digital voltmeter or a multimeter. To obtain a stable voltage, the battery should not have been used or charged for 3 hours at least before checking the voltage. If the voltage is below 12.40V, charge the battery in accordance with Section 4.


The color of indicator presents the status of battery. You are noticed when to charge or change a battery by indicator.


Good to use continuously


At first, Shake a battery then check the color again. Otherwise the battery needs to be charged.


It means that life comes to an end or electrolyte is evaporated by over charge. Need to replace a new battery.

3. New Battery Installation

Handles with care

  • Check the battery on leak and damage.The defective battery causes a burn or an electric leakage.
  • Replacing the old battery with the new same one is highly recommended.
  • Installation of a battery with the same layout of a car is preferable.Otherwise, it causes damage to cable or fire.
  • Use protective gloves when transporting a battery in order to prevent a skin burn or injury.
  • In case of installing 2 batteries in a car (Such as Bus & Truck), do not use different or new battery from the old one in the car. If not, it is causative of damage to the car.


  • The replacement of a battery should be done safely and in order.
  • Turn off the engine and remove the key.
  • Need to be careful of short circuit when removing the cable from the terminal.
  • Brush the cable and the battery holder.
  • Carefully use tools to prevent short circuit.
  • Fasten the terminal clamp and battery holder as much as you can in order for it not to be shaken.
Recommend Torque Value
Battery holder Top bar or top frame hold-down 30-50 inch-pounds
Bottom recess type hold-down 60-80 inch-pounds
Bottom ledge type hold-down 70-90 inch-pounds
Battery holder Tapered terminal posts (SAE) 50-70 inch-pounds
Stud terminals 70-90 inch-pounds
Bottom ledge type hold-down 120-180 inch-pounds

Procedure of battery replacement

Place your car on flat ground.
Turn off the engine and remove the key.
(In case of remote control key, open windows not to be locked)
Open the hood and check the battery.
Remove cable from negative terminal first, and then from positive terminal of the used battery.
– Disconnect the battery holder.
– Brush clamps
Place a new battery on installation rack and secure it by tightening bolts. Make sure if the battery is fixed completely by pressing it with hands.
Connect cable with positive terminal first, and then with negative terminal
Start the engine and check whether the attery is working properly.

4. Charging Methods

Check the state of Charge

Check the indicator to see if the battery is okay, needs to be charged or requires replacement. A voltmeter is preferable for exact check.

Criteria for recharge

If the indicator shows black color, it is necessary to be recharged. And in a general case, it is necessary to be recharged if voltage is under 12.4V.

Constant Current Charging

Calculation of auxiliary charging amount
Charging amount
C = C20 * D * 1.2
  • ⓐ C : Charging amount (Ah)
  • ⓑ C20 : 20Hr rate capacity
  • ⓒ 1.2 : 120%(coefficient)
  • ⓓ D : Discharging amount(%)
Charging time
T = C / A
  • ⓐ T : Charging time(Hr)
  • ⓑ C : Charging amount(Ah)
  • ⓒ A : Charging current(A)
        (A = C20 * 0.05)
Ex) MF80D26L(70Ah / 20Hr) Open circuit
voltage 12.40V How to charge?
  • ⓐ Charging amount : 70Ah * 0.25 * 1.2 = 21.0Ah
  •     (25% discharged; see TABLE 1)
  • ⓑ Charging current : C20 * 0.05 = 3.5A (see TABLE 2)
  • ⓒ Charging time : 21.0Ah / 3.5A = 6.0Hr

TABLE 1. State of charge
O.C.V [V] Approximate State of Charge
12.75 100%
12.40 75%
12.20 50%
12.00 25%
11.90 Discharged
TABLE 2. Charging Current according to state of charge by battery capacity.
State of Charge O.C.V [V] ~ 40Ah
~ 50Ah
~ 60Ah
~ 70Ah
~ 80Ah
~ 90Ah
~ 100Ah
100% 12.75
75% 12.40 6Hrs
50% 12.20 12Hrs
25% 12.00 18Hrs
Discharged 11.90 24Hrs
Lack of Acid

Constant Voltage Charging

  • ⓐ Voltage : 14.4 ~ 16.0V
  • ⓑ Current : Under 10A
  • ⓒ Charging Time : Over 12Hr (General battery)
  • ⓓ End the charge
        The following points will tell you if a battery has been properly charged :
         – Indicator is green and current is below 1.0A during charge.
         – Open circuit voltage is stabilized at or above 12.7V.


  • ⓐ Connect positive (+) charger cable to positive (+) terminal of battery.and negative (-) charger cable to negative (-) terminal
  • ⓑ Always charge batteries in a well-ventilated area.
  • ⓒ If violent gassing or spewing of electrolyte occurs, temporarily reduce or halt charging. (Possible battery failure)
  • ⓓ The temperature of battery must be lower than 50℃.If temperature increases over 50℃, pause charging for several(1~2) hours and then continue at the temperature below 50℃.

5. Jump Starting

Before proceeding, read safety precautions in Section 1.
Warning – Batteries produce explosive gases.
These instructions are designed to minimize the explosion hazard while jump-starting a car. Keep sparks, flames and cigarettes away from batteries at all times.
Shield eyes and face at all times. Never lean over the battery when jump starting.
Inspect both batteries before connecting booster cables and do not jump start a damaged battery.
Make sure the vehicles are not in contact with each other.
Turn off all electrical equipment (radio, defroster, windshield wipers, lights, etc.).

The following steps should be proceeded:

ⓐ Connect positive (+) booster cable to positive (+) terminal of discharged battery.
ⓑ Connect other end of positive (+) cable to positive (+) terminal of assisting battery.
ⓒ Connect negative (-) cable to negative (-) terminal of assisting battery.
ⓓ Make final connection of negative (-) cable to engine block of stalled vehicle,away from battery and carburetor.
ⓔ Make sure that cables are away from fan blades, belts and other moving parts of both engines.
ⓕ Start vehicle and remove cables in reverse order of connections.

* See diagram below for proper hookup.

For more information, contact DTR representative.