http://davidernst.net/blog/2009/01/12/battery-inequality/ Things I'll talk about with anyone Mon, 01 Mar 2010 15:32:46 +0000 hourly 1 http://wordpress.org/?v=3.3.1 http://davidernst.net/blog/2009/01/12/battery-inequality/comment-page-1/#comment-17521 Ted Wed, 28 Jan 2009 20:41:23 +0000 http://davidernst.net/blog/?p=134#comment-17521 My understanding of Battery physics is that what happens is as a battery discharges its internal resistance increases. As the internal resistance increases the power available to power the device goes down because some of the power is being lost as heat. This is why you want to replace all of the batteries at the same time because even though only one "tests bad" it tests bad because it was the weak link and the other batteries provided power to heat it up. The remaining batteries all have increased internal resistance too, just not enough that the tester says they are bad, so now the new battery has to heat up all of them as well as provide power to the device. The new battery will not last as long doing this. Of course application might make a difference, if you had battery heated socks, it probably doesn't matter much (for example). My understanding of Battery physics is that what happens is as a battery discharges its internal resistance increases. As the internal resistance increases the power available to power the device goes down because some of the power is being lost as heat. This is why you want to replace all of the batteries at the same time because even though only one “tests bad” it tests bad because it was the weak link and the other batteries provided power to heat it up. The remaining batteries all have increased internal resistance too, just not enough that the tester says they are bad, so now the new battery has to heat up all of them as well as provide power to the device. The new battery will not last as long doing this. Of course application might make a difference, if you had battery heated socks, it probably doesn’t matter much (for example).

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