Dry Charge Battery Performance Issue
Prepared by : Nuruddin ( Production Engineer)
Date : 28th Jan 14
Dry Charge battery should perform cranking performance more than 60 days.
A. Control at dryer positive
- Dry-charged batteries suffer the most energy losses after formation, while the wet-charged batteries are less affected.
- Discharge voltage of the battery decreased with increase of the drying temperature.
(1) 25-80 C = low temperature region. The plates retain their energy, in terms of both mean discharge voltage and discharge time.
(2) 80-220 C = thermopassivation region. Thermopassivated plates retain their capacity, but the energy and power of the battery are reduced.
(3) > 250 C = thermal disintegration region. A lot of PbO formed (semiconductor layer).
B. Control mositure content
According to : Lead-Acid Batteries: Science and Technology: Science and Technology, D. Pavlov (page 546)
Moisture positive form recommend = < 0.2 %
Moisture negative form and saparator recommend = < 0.05 %
During storage, with high humidity in container,
- Oxygen evolved at positive plate during storage.
- The oxygen react with humidity oxidize Pb to PbO.
- Especially negative plate will effected (pure lead)
- The PbO react with residual H2SO4 to form PbSO4 (passivation layer)