Thread: Dead battery!
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Unread 07-02-2005, 13:57
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Al Skierkiewicz Al Skierkiewicz is offline
Broadcast Eng/Chief Robot Inspector
AKA: Big Al WFFA 2005
FRC #0111 (WildStang)
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Re: Dead battery!

Quote:
Originally Posted by krhs_programmer
We went to disconnect the battery and when we grabed the connector we drew back in pain because it was burning hot! We let it cool and disconnected it and put the volt meter on it and it read .25 volts. The battery went from fully charged at 13.4 volt to .25. Please explain this!
There is something missing from this picture...The hot connector and dead battery would indicate a dead short somewhere after the main breaker (since that tripped) but you have said nothing about any of the other breakers tripping. So this leaves us with a dilemma, what could be wrong?
1. The breaker panel itself shorted. (doubtful without some other visible sign. i.e. smoke and flame.)
2. Wiring between the main circuit breaker and breaker panel shorted. (most likely cause, might be a main breaker that is not secure and moves against the frame.)
3. Not using the breaker panel or not using the specified 40, 30 and 20 amp breakers in series with the motor types used for this season. (Not likely, teams don't bypass safety features like a breaker panel and specified breakers.)

You have not mentioned that you tried a new battery and all was OK so I am assuming that you are still troubleshooting before connecting a known good battery. I would disturb as little as possible, remove all the breakers from the panel, and measure the resistance at the robot end of the battery connector. It should be infinite regardless of whether the main breaker is closed or open. If it reads less than a few thousand ohms with the main breaker closed, but not open, your problem is after the breaker. Disconnect the breaker panel and test again, if the resistance reading goes high, than suspect the breaker panel.
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Al
WB9UVJ
www.wildstang.org
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