DTR AUTOMOTIVE

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Directions for Battery Maintenance

We have collected our know-hows for optimal
DTR Automotive battery maintenance.

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.
  • 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.
* Battery charging requires extreme caution. If you do not have sufficient knowledge or experience, please consult a store or help center for service.

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
OCV [V] Approximate State of Charge
12.75 100%
12.4 75%
12.2 50%
12.0 25%
11.9 Discharged
TABLE 2. Charging Current according to state of charge by battery capacity.
State OCV [V] ~ 40Ah
2.0A
50Ah ~
2.5A
~ 60Ah
3.0A
~ 70Ah
3.5A
~ 80Ah
4.0A
~ 90Ah
4.5A
~ 100Ah
5.0A
100% 12.75
75% 12.4 6Hrs
50% 12.2 12Hrs
25% 12.0 18Hrs
Discharged 11.9 24Hrs

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.

Notice

  • ⓐ 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)
  • ⓒ If violent gassing or spewing of electrolyte occurs, temporarily reduce or halt charging. (Possible battery failure)