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Originally Posted by KenWittlief
If you put a different style of connector on your two new batteries, then where are you going to get fresh batteries from when you make it into the elimination rounds, and might have to play 3 or 4 matches with only a 5 minute break between them?
FIRST supplies charged batteries during the elimination rounds and the finals. If you dont have the same connector you would have to buy several new batteries and bring them all, keep them all charged...
you defintely dont want to use last years batteries during a match - they do lose capacity - any gain you had from a superiour connector would be lost by the weaker (old) batteries.
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First, as Justin stated, FIRST does not officially provide batteries for the finalists since 1998. It is possible that the event staff had some batteries you could use, but that is event specific. You do have a valid point about borrowing batteries, though, but it is not hard to work around at all. You just create a short piece that has both one of your new connectors and one of the FIRST connectors. Then, just put that inline with your borrowed battery and your robot.
Now, as an engineer, lets look at the ratings of the provided connector, the battery, and the circuit breaker. The battery can provide 230 amps for 5 seconds (per the data sheet posted by FIRST). That's not a problem, though, because we have a circuit breaker that will cut off at 120 amps, right? No, per the data sheet posted by FIRST, the breaker will provide 200% of its rated current for 10 seconds, which means that the battery can short, and the breaker will never trip. Now lets look at the ratings of the connector. Its an Anderson Power SB 50. You can get the data sheet from
http://www.andersonpower.com. You will see that the connector is rated for 50 amps, and will withstand 230 amps for less then 1 second. So, the battery can provide that current for 5 seconds, and the connector can withstand it for less then 1. There is some saftey margin involved, but is it 5x or greater? For the answer to that, I point you to this picture:
http://www.chiefdelphi.com/forums/pi...gle&picid=3832
Do most teams get away with it? Yes. Is it good engineering practice? I don't think so. Your connectors should be rated to be safe during a short. However, even if you don't short your batteries, but run at 80 amps for 30 seconds, you still exceed the current capability.
On a somewhat unrelated note, team 696 lost the Fall Classic because thier battery disconnected in the middle of a match. So, definetly make sure that whatever connectors you do chose don't come undone easily.