sikui Posted June 8, 2006 Report Share Posted June 8, 2006 Common to all types of rechargeable batteriesis there is such thing called "self discharge" where the battery actually loses power even though the device it's in is turned off. Is there a "common" rate of self discharge (which it varies between capacity and its chemistry) eg 90% capacity after 60 days (i.e loses 10% capacity)? ??? ??? ???Any1 can help? Quote Link to comment Share on other sites More sharing options...
Ldanielrosa Posted June 9, 2006 Report Share Posted June 9, 2006 With nickel chemistries, 1% per day. Maybe more early on. Quote Link to comment Share on other sites More sharing options...
audioguru Posted June 9, 2006 Report Share Posted June 9, 2006 The self-discharge rate is higher with Ni-MH batteries as compared to Ni-Cad.The self-discharge rate is also higher with higher temperatures, so keep the battery away from sunshine. Quote Link to comment Share on other sites More sharing options...
sikui Posted June 11, 2006 Author Report Share Posted June 11, 2006 Thank you for the replies. I was told by my U lecturer that a Ni-Cad rechargeable battery 12V 600mAH when new and is fully charged will be able to retain its capacity for at least 3 months (not in use) Quote Link to comment Share on other sites More sharing options...
audioguru Posted June 11, 2006 Report Share Posted June 11, 2006 Energizer has a Ni-Cad Applications Manual on their website. It shows a graph of self-discharge that is much quicker than you have been told. Quote Link to comment Share on other sites More sharing options...
sikui Posted June 16, 2006 Author Report Share Posted June 16, 2006 Thank you Audioguru. Need further clarification on the graph result - the top end graph curve is it for new battery? and bottom end curve is for used battery???Is there any test which can be carried out to know the rechargeable battery is holding its charge and amperecity? Quote Link to comment Share on other sites More sharing options...
audioguru Posted June 16, 2006 Report Share Posted June 16, 2006 Need further clarification on the graph result - the top end graph curve is it for new battery? and bottom end curve is for used battery???The top left is a fully-charged Ni-Cad battery.The graph shows how much charge (capacity) is retained after sitting for weeks. The graph has a range (28% to 77% at 12 weeks) because all batteries are a little different. Just put a load on it and time how long the battery charge lasts. Most Ni-Cads are rated in mA/hrs at a 1/10th C rate. Look at the graph to see if a battery holds its charge (they don't). Quote Link to comment Share on other sites More sharing options...
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