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Unread 26-04-2010, 11:16
Unsung FIRST Hero
Al Skierkiewicz Al Skierkiewicz is offline
Broadcast Eng/Chief Robot Inspector
AKA: Big Al WFFA 2005
FRC #0111 (WildStang)
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Rookie Year: 1996
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Re: Automatic load tester for batteries

Typical intermittent current draws can go into the 400-500 amp range but are very short duration. The seven amp continuous draw is a good alternative when trying to approximate the manufacturer's spec and maintain battery life. The more you pull from a battery and the number of charge/discharge cycles tends to reduces the battery from about 400 cycles (typical) to something less. I am guessing as low as 200 but with care 300 or more cycles. You can compare Enersys and MK charts and you will see that they differ in curve units but essentially produce the same curves for both battery types. A bad battery will show good for 15 seconds but may die by one or two cells after that.
Check this post http://www.chiefdelphi.com/forums/sh...6&postcount=19 for a plot of several batteries tested with the CBA. The black curve is a good battery plotted against a battery that has two cells die after some time, a battery with an intermittent connection internally and a battery that has two cells die almost immediately. For a short, high current test, all of these might show the same.
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Good Luck All. Learn something new, everyday!
Al
WB9UVJ
www.wildstang.org
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Storming the Tower since 1996.