Title :
Premature capacity loss in VRLA batteries for telecom applications
Author :
Okada, Yuichi ; Tsuboi, Yuichi ; Shiomi, Masaaki ; Osumi, Shigeharu
Author_Institution :
Japan Storage Battery Co. Ltd., Kyoto, Japan
Abstract :
The effect of depth of discharge (DOD) and discharge frequency on premature capacity loss (PCL) in valve regulated lead-acid (VRLA) batteries for stand by use was investigated. PCL showed a tendency to occur when batteries were discharged frequently to a shallow DOD. In order to clarify the reason of this result, changes of interfaces between positive grids and positive active materials (PAM) after charge-discharge cycles were investigated. It was found that PCL was a phenomenon due to the increase of the resistance between the positive grid and the PAM. PCL occurred when the adhesion between the grid and the PAM was poor, the concentration of H/sub 2/SO/sub 4/ around the grid/PAM interface was higher than the PAM and the corrosion layer was mainly consisted of /spl beta/-PbO/sub 2/.
Keywords :
corrosion; hydrogen compounds; lead acid batteries; lead compounds; losses; sulphur compounds; telecommunication power supplies; H/sub 2/SO/sub 4/; PbO/sub 2/; charge-discharge cycles; depth of discharge; discharge frequency; positive active materials; premature capacity loss; valve regulated lead-acid batteries; Adhesives; Batteries; Capacity planning; Corrosion; Frequency; Gravity; Telecommunications; US Department of Defense; Valves; Voltage;
Conference_Titel :
Telecommunications Energy Conference, 2003. INTELEC '03. The 25th International
Conference_Location :
Yokohama, Japan
Print_ISBN :
4-88552-196-3
