· 5.1 Two Stage charging (Constant current to Constant voltage)
This is the recommended method of charging SLA batteries. It is necessary to strictly control the actual charging voltage to ensure it is within the appropriate safeguards.

Fig 5.1 shows the charge characteristics at a constant current (0.1C(A))and a constant voltage 2.40V/(cell)after discharge of 50% and 100% of the 20HR rated capacity.

The time required to complete the charging varies by the amount of the previous discharge, initial charge current and temperature.

As shown in Fig 5.1 if a fully discharged battery is charged by constant current and constant voltage of 0.1C(A)and 2.40V/cell respectively at 25 ℃ , it will regain more then 100% of the previous discharge within 24 hours.

Since the battery does not restrict the initial charge current, this shortens the charging time.

· Fig 5.1 Charging characteristics(25 ℃ )
· 5.2 Floating Charge
Floating charge voltage must be kept at a value high enough to compensate the battery self-discharge so the battery can be in a fully charged condition at all times.

The optimum charge voltage for Kedi Battery is 2.25V per cell under normal temperature conditions (25 ℃ )

· 5.3 Supplementary Charging
Part of the battery capacity will have been lost due to self-discharging during transportation or storage. Give the battery a supplementary charge before putting it into service.

The supplementary charge should be given by every six months according to the charge conditions in Table 5.1.

· Table 5.1: Supplementary Charge Conditions