Operation; Charge Cycle - Kohler GM87448 Operation

This section describes the battery charger operation and transition states and includes the voltage and current parameters for
those states. The operation states are indicated by the LED indicator lights. Refer to the LED Indication chart in the
Troubleshooting section.

3.1 Charge Cycle

The operation sequence begins with the charger detecting the voltage applied across the output and automatically determining
the proper charging voltage. Voltage with less than 18 volts selects the 12-volt charging profile, where voltage higher than 18
volts selects the 24-volt charging profile. Once a valid battery is detected, the charger begins charging the battery by entering
the Bulk Charge state. A steady red LED light for output voltage indicates Bulk Charge state.
If a battery is not detected, the charger periodically attempts to locate a battery or voltage source. The red and green Output
State LEDs blink indicating when the charger is performing this function.
If a reverse connected battery is detected on power up, the charger does not energize the output. The Output State LEDs go
dark indicating the reverse battery is detected and is waiting for the condition to be removed. The battery charger can tolerate
a reverse battery connection without damage to the battery charger or blowing the fuse.
Note: SiteTech™ can be used to verify the reverse battery condition.
If the battery charger is temporarily disconnected from an AC power source, the charger automatically resumes operation in
Bulk Charge state.
WARNING
Use the following definitions to understand the charge states and operation sequences. Charge states are controlled by the
parameter settings. The transition states, when the battery charger transitions from one charge state to the next, are listed
directly below the charge states. Refer to the section on Default Voltage and Current Parameters.

Recovery Charge – If the attached battery or voltage source is below the depleted battery voltage parameter, the
battery charger enters the recovery charge state. This is also called low voltage charging. The depleted voltage is
defaulted to 10 V for 12 V systems and 20 V for 24 V systems. During this charge state, the red LED for output
voltage blinks to indicate that the attached battery is not in a normal state.
Recovery occurs when voltage is below the depleted battery voltage parameter.
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From Recovery to Bulk occurs when the voltage rises to above the depleted battery voltage parameter.
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
Bulk Charge – Once a valid battery is detected, the battery charger begins charging the battery by entering the bulk
charge state. In the bulk charge state, the battery charger outputs a constant power charge algorithm indicated by a
steady red LED for the output voltage. In this state, the battery charger outputs approximately 125 W for a12 VDC
system and 250 W for a 24 VDC system. The battery charger always enters this state on power up after a good
battery is detected. The battery charger remains in bulk charge for a minimum duration of 30 seconds. Upon reaching
the bulk voltage parameter, the battery charger begins to regulate voltage instead of power. When this point is
reached, the battery charger enters the absorption charge state. See the following transition state:
From Bulk to Absorption occurs when the battery charger output is above the bulk voltage parameter
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setting minus 0.20 V and the battery charger has been in bulk for the minimum bulk time.

Absorption Charge – When in the absorption charge state, the battery charger is maintaining a constant voltage
equal to the absorption voltage parameter. The battery charger current reduces as the battery completes its charging.
When in this state, the output voltage LEDs switch to solid red and solid green. The battery charger remains in the
absorption charge state for a minimum of 30 seconds.
As the current drops below the return amps parameter level. The battery charger switches to float charge. If the
maximum absorption charge timer expires, the battery charger is forced into float charge state to protect the battery
from over charging.
From Absorption to Float occurs when current is below the return amps parameter threshold and the
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battery charger has been in absorption charge state for the minimum absorption time unless the equalize
charge state has been activated when maximum absorption timer expires.
From Absorption to Equalize occurs if equalize charge state is enabled and the battery charger current is
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below return amps and battery charger has been in absorption charge state for the minimum absorption
time.
From Absorption to Bulk occurs while in the absorption charge state if the load increases causing the
o
battery charger to go back to current/power limit, the battery charger should go back to bulk charge state.
TP-7077 3/19
Hazardous voltage.
Will cause severe injury or death.
Switching off the charger does not cut off the connection to the batteries or the AC power
source. When switched off, voltages are still present inside the battery charger apparatus.
Section 3. Operation
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