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 sunnyway 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

· 5.4 The Charging Voltage And Ambient Temperature Relationship
The charging voltage should be 2.40 volts per cell at 25℃. However, as the average ambient temperature rises, the charging voltage should be reduced to prevent overcharge. As the average ambient temperature is reduced, the charging voltage should be raised to prevent under-charging. Accordingly, the recommended compensation factor is-3mV, per cell at 25℃ of the standard point.