Kohler 20EKOZD

TP-6953 7/19170 Section 9 Component Testing and Adjustment
9.11 Battery Charging Module,
13- 24EKOZD/12- 20.5EFKOZD
Original (12/24 Volt: GM77373)
Note: For generator set variation numbers with serial
numbers before:
GM102825-MA1: 336KGMGG0006
GM102825-MA2: 337PGMGG0015
GM102825-MA3: 337XGMGG0018
GM102825-MA4: 337XGMGG0009
The junction box contains a battery charging module to
maintain the engine starting battery. The battery
charging module monitors the battery voltage and
provides 8 amps to charge the battery and capable of
charging a 12 or 24 volt battery.
Note: The battery charging module is reverse-polarity
protected.
Before testing the battery charging module, ensure that
no other DC loads are o n the generator set. At startup,
after approx. 1 min., check for a change in voltage. If
voltage increases, the battery charging module is
functioning. If voltage decreases, the battery c harging
module is inoperative.
1
GM82844-D
1. LED1 (red), reverse battery
2. LED2 (green), power
2
Figure 9 -18 Battery Charging Module (GM77373)
9.12 Battery Charging Module,
13- 24EKOZD/12- 20.5EFKOZD
Revised (12 Volt: GM105398
and 24 Volt: GM105399)
Note: For generator set variation numbers with serial
numbers shown below and later:
GM102825-MA1: 336KGMGG0006
GM102825-MA2: 337PGMGG0015
GM102825-MA3: 337XGMGG0018
GM102825-MA4: 337XGMGG0009
Figure 9-19 Battery Charging Module (GM105398
and GM105399), Typical
The junction box contains a battery charging module to
maintain the engine starting battery. The battery
charging module monitors the battery voltage and
provides 8 amps to charge the battery.
9.12.1 Three Stage Charge Cycle
The battery charger uses a three stage charge routine
that most lead-acid battery manufacturers recommend
to return full capacity efficiently and to extend battery
life. See Figure 9-20. The charger is capable of
charging a battery from zero volts.
Note: A battery left in the zero volt condition for an
extended period of time will sulphate and lose
capacity.
Stage 1: Fast Mode (Bulk)
Assuming that the battery is starting in a discharged
state, the charger is operating in constant current mode.
The charger current is maintained at a constant value
and the battery voltage is allowed to rise as it is being
recharged. Approximately 80% of battery capacity is
returned in the constant current region.
Stage 2: Top-Off Mode (Absorption)
When the battery voltage reaches approximately
2.4 volts per cell, or 14.4 volts for a 12 volt battery and
28.8 volts for a 24 volt battery, the charger voltage is held
constant at this level and the battery current is allowed to
reduce. This voltage is maintained until the charging
current reduces substantially indicating a full charge. At
this point, the battery is fully charged.