regarding your cordless drill battery , a lot of drill batteries after continued charging and discharging become weak one of the reasons that i found is that if anyone of the single cells breaks down ,the battery will charge up but will get hotter than normal and will only last for a short time , there for aquire a small test meter if possible and check each cell in turn they should read 1,2 volts when charged, if one of them does not read then it is the faulty one ,hope this helps
jim, January 2010
