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Unread 05-11-2002, 00:29
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Honestly, my team has always gotten at LEAST three matches out of a battery before the voltage indicator on the OI starts to even drop a little. Here's some fun math stuff:

The batteries we use are 12Ah @ 1hr discharge rate
Extrapolating since we drain significantly faster than that gives about 10Ah in practice.

10Ah is 600Amin (amp-minutes. I made the unit up myself!) A match is 2mins. Thus, to drain a full battery in one match would require a continuous current draw of 300amps. Given that the main breaker will trip at just 60amps sustained, I don't see this as being even remotely possible. Even draining a battery in two matches would require 150amps, which is 150% of the maximum sustained discharge rate of the battery.

Assuming you could prevent the breaker from tripping, the battery still won't output more than 100amps continuous (450 short-duration). Taking a weighted average, lets figure on 110amps max average draw. At 600Amin, that would be 5.5mins, which is almost three whole matches.

Assuming the max draw is 60 (as limited by the breaker), we get 10mins, albeit that the breaker will sustain higher amperage currents for short periods of time.

The only way I can realistically forsee needing to change a battery after every match is if you drive train is horribly twisted and inefficient or if you are dealing with old batteries. Given that most teams (I think/hope), don't even touch the batteries in the kit of parts until the competition, I don't really see that as a possible explanation either.
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