On 23/01/2011 19:45, V G wrote: > On Sun, Jan 23, 2011 at 1:39 PM, Olin Lathropw= rote: > >> This is getting ridiculous. Once again: >> >> If the charging regime is according to the datasheet, then assume no >> damage. >> >> If the charging regime is not according to the datasheet, then you have = to >> assume damage. Asking exactly how much damage you will cause by violati= ng >> the specs is pointless. Or put another way, if you have to ask, assume = the >> answer is "significant damage". >> > > Well, that's what I'm asking. Obviously, overcharging at 100 mA won't ca= use > as much damage as overcharging at 2000 mA. That's what I'm asking. In you= r > experience, how much damage can be done if the person leaves it on past t= he > end of charge with a 150 mA charger for a few hours. I think this kind of thing is difficult to quantify easily, so you have=20 to rely on what the manufacturer datasheets specify, unless you are=20 willing to go to the kind of lengths they do to provide the maximum=20 ratings, performance graphs etc. Certainly in the case of producing a product commercially (or anything=20 you wish to have confidence in) it's very advisable to assume that=20 anything outside these limits will be a problem, and as mentioned "how=20 much or little of one" is not really worth thinking about - (basically=20 you have to assume the worst will happen) As far as the actual question goes, from what I have seen/read I think=20 NiMH are quite sensitive to overcharging and the effects are capacity=20 decrease over time (even with small amounts), hydrogen build up and=20 excess heat increasing to possibly dangerous levels with heavy=20 overcharging. It mentions on the Wiki that some manufacturers consider=20 permanent overcharging at up to 0.1C to be possible. I think at 150mA for a few hours extra it will *probably* just reduce=20 the capacity a little with no catastrophic failure, but best to read up=20 and draw your own conclusions, loads (possibly too much.. :-) ) of info=20 out there - the "battery university" site is a good place (plus=20 candlepower forums - and I guess the eneloop site too will have info=20 specific to their brand, which I believe has a slightly different=20 design, so possibly slightly different charging advice) --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .