Constant Current Charger - IUI

A constant current charger can also be used, however it is important to adhere to the termination criteria mentioned below to minimize the chance of excessive over-charge. See Figure 2 for the recommended constant current charge profile.

Bulk Stage

The charger should deliver the initial current I1 until the voltage limit U0 is reached.

Absorption Stage

The charger should maintain the voltage U0 until the current tapers to I1

Termination

If the charger can be programmed, the charge should terminate when the voltage stops increasing over time. This is called a dV/dT termination. The charge should terminate when the dV/dT is equal to 2.5mV/cell/hour. The charge time in the final phase should not exceed 8 hours and the total charge time should not exceed 20 hours. The percentage recharge should be between 105%-110%.

Refresh Charge

If Rolls batteries are properly charged they should never require an equalizing charge. If they were not properly charged and there is a decrease in capacity, recharge the batteries and make sure they complete the entire charge cycle. If the batteries are stored for extended periods of time, recharge them as follows: