On 1 September 2014 02:47, Luis Moreira wrote: > ... > alarming on low voltage and when I check, it was quite low on voltage. > I tried to charge it and although the charger is saying it is charged as > soon as you remove it, the voltage drops of straitway. > Today I removed the caps and charged it again but noticed that one of the= 6 > cells is not bubbling up. > Does this means that, that cell is shorted? Is it anyway I can repair it= ? _______ > Collection of disparate thoughts follow which may or may not be relevant: What 'quite frequently' happens is that the conduction path is broken somewhere inside the battery. This can happen if you hit a "bump" at high speed (ask me how I know :-) ) or otherwise cause a large physical impulse to the battery . I've read [tm] that a significant % of battery failures are for this reason. Auto batteries in rough use apparently fail often in this manner and AIUI spiral plate construction (eg CYCLON? *) batteries are far less prone to this failure mode. I do not know where the weak points are or if it is the cell to cell interconnects that fail (seems most likely) or if a partial cell can disconnect. While the latter seems less likely it would leave one cell with low capacity and it would probably emulate what you see. (The equivalent situation occurs in PV panels with series cells where one cell fractures part way along its length). If a battery cell is fully shorted you would expect the maximum voltage that it would exhibit just after charge is removed to be substantially lower than if all cells were present Russell * http://www.enersys.com/Cyclon_Batteries.aspx --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .