Thread: Battery Smoke
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Unread 15-05-2007, 21:41
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Jeff Pahl Jeff Pahl is offline
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FRC #5148 (New Berlin Blitz)
Team Role: Engineer
 
Join Date: Oct 2004
Rookie Year: 2004
Location: Waukesha, WI
Posts: 344
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Re: Battery Smoke

Quote:
Originally Posted by Al Skierkiewicz View Post
I think it is appropriate to discuss this now so teams know for next year. There were three battery incidents in Atlanta that I know of. Team A & Team B both designed battery trays such that the battery mounts on it's side. In both cases, a battery was inserted into the robot with the terminals down against the the frame. The result was that the frame (aided by the battery weight) pierced through the insulation (yes both terminals on both batteries were insulated) and the frame provide a nice low resistance short to the battery. Team A's battery swelled in all directions and distorted the case while providing significant heat. (It was a practice battery) Team B's battery provided so much heat that the positive battery terminal (which is soldered inside the case) detached from the internal terminals and pulled out of the battery. Both teams had designed the tray so that a battery when mounted with the terminals up had no problems. Just a simple mistake in the heat of battle.
Team C was having some trouble with one of the battery connectors and decided to bend the terminals inside the Anderson connector to make things easier. (don't do this at home) In the process, one (or both) of the terminals was released and backed out of the block producing a high resistance connection. Eventually it appeared that terminal pulled back far enough that it contaced the opposite terminal and shorted the battery.
Pictures will be added when they become available.
Here (finally) are the pictures of Team B's battery and Team C's connector to go with Al's description above:

The right Anderson connector was disected to determine the cause of the connectors being welded together. The terminals had backed far enough out of one of the connectors after being bent to only form a high resistance connection. The team became involved in a pushing match, which resulted in a lot of smoke and the connector becoming welded together.
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