The battery charge cycle changes with the parameters:

• I-Method

Charge with constant current without voltage control. Only applicable when charging with small currents - otherwise battery damage may occur due to high temperature and resulting water loss. At the end of the charge cycle the current is removed manually - (turning the charger off). Due to the long charging period this method is only suitable for first time installation of the battery.

• Ia-Method

This is a charge method identical to constant current without voltage control mentioned above, the difference is the automatic stop at the end to the charge cycle. This is   usually at the end of a predetermined time period (timer).

• U-Method

Charge with constant voltage, when the voltage threshold is reached the current is reduced automatically.  This charging method reduces the charge cycle typically between 7 - 9 hours. 

• IU-Method

This charge method starts with a constant current until the battery reaches the gassing voltage, after which a transformation occurs and the charger continues its cycle with a constant voltage instead. The constant voltage is maintained below the gassing threshold (2.4V per cell). In this manner the current is drastically reduced so that overcharging the battery never becomes a concern. The charging cycle depends on the beginning current setting.

• W-Method

The charging cycle depends on the batteries internal resistance. In this method the current is reduced and the voltage increases. After reaching the desired threshold the charger is turned off (manually). 

• Wa-Method

This charging method also utilizes the batteries internal resistance. The current is reduced and voltage also increased until reaching the desired threshold. The charger is turned off automatically (timer) usually between 10 - 12 hours.

• IUIa-Method

The charge method allows the current to be constant until the gassing threshold of 2.4 V is reached. After which the method switches to constant voltage and a reduction of the current. After reaching a specified level charging resumes with constant current until the end of the cycle when the battery is replenished. At this point the charger turns itself off.