30
WhisperPower
Lithium Plus 12 V 210 Ah 340 Ah
5.2.2. Charging method
Whisper Power recommends using the following charging method.
Charge Profile Whisper Power Batteries
Figure 19. Charge curve
Bulk phase
In this phase the batteries are charged with a constant current up to the end of charge
voltage (Ubulk), If UBulk is reached the charger will automatically switch to absorption
phase. The maximum charge current (Imax) for Whisper Power batteries is 1C, however
for endurance cycle life Whisper Power suggests to limit the current to C3 (1C = nominal
battery capacity, C3 = 1/3 of nominal capacity). On some chargers the maximum charger
active time (t0) can be programmed. Whisper Power suggests setting t0 to: t0 = 2*(BTcap /
Chcur)
Example: Battery capacity = 210 Ah, Charger = 100A, Set to a maximum of 2*(210/100) =
4.2 hours.
Bulk Phase
Typical
Min
Max
I
max
-
-
1C (210 A)
t
0
Depends on the battery SoC
-
2*(BTcap / Chcur)
Table 8. Bulk Phase
Absorption phase
In this phase the charge voltage must be maintained at UAbsorption to fully charge the
Lithium battery and set the State of Charge (SoC) counter to 100%. See Table 7. This phase
is finished when the SoC is indicating 100%.
