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Unread 17-12-2010, 18:43
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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Re: Warming up the batteries

The curves are generated at 7 amps or about 0.5 C (see curve menu at right side of graphs). From the CBA webpage...
"Unlike a resistor load it has an electronic constant current load that is controlled both with software and electronics."
I don't think taking a reading after removing the load will give any valid information. I do not recommend that anyone use a voltmeter alone to evaluate the state of charge on an SLA battery. The input impedance of modern voltmeters is sufficiently high to prevent an accurate reading across the internal impedance of the battery. As this "resistance" changes with battery age, temperature and state of charge, the load test will tell exactly what the battery is capable of delivering in a curve that can be compared with both the published battery data and with past tests of the same battery. The one amp shown was generated when I overlayed the four previous tested battery curves onto a single page within the program.
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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.

Last edited by Al Skierkiewicz : 17-12-2010 at 18:46.