In batteries with removable caps (non-sealed), the charge time –at temperatures 20°C to 35°C– depends upon reaching an electrolyte density of 1280 g/cm3 in all cells. Charging is complete once this value is established. After letting the battery sit for 30 minutes, adjust the electrolyte level to its maximum level, wipe the top, and then install the battery. Wet-charged batteries or customer's discharged batteries are charged according to the current levels and time periods given in the table below. Note that used batteries may not be able to reach the desired density level. In such cases, if the adjusted density remains unchanged in the last two hours, charging is considered satisfactory. Sealed batteries without removable caps (maintenance-free) are charged in accordance with voltage values.
1. Make sure the charger is turned off.
2. Measure state of charge of the battery.
3. Hook up the charger to the battery. Connect positive charger clip to positive post of battery, and negative to negative. Make sure you always look at the battery and determine the positive by the plus sign and the negative by the negative sign.
4. Select desired current and voltage in accordance with your chargers settings and instructions provided in manufacturer's manual. Start charging.
5. Once the charging is over, turn off the charger before disconnecting the clips.
6. To determine whether there is need for additional charging, measure open-circuit voltage and cell densities.
You can parallel charge several batteries of same capacity, simultaneously.