[Al Skierkiewicz]

Michelle,
The amp/hr rating is usually specified at about 1/10 C or in this case, using the charge current Chris specified, 900ma. So under continuous discharge, 3000ma/hr and 900ma load, about 3 hours. I am guessing our use will be in the order of 5-6 amps for two motors, so with a little derating for increased current, I am guessing 30 minutes. Since we are only going up and should get there in 5-7 seconds, that's about 257 matches. If teams were drawing 10 amps for two motors, that would reduce to under 20 minutes or about 171 matches. Putting your batteries on charge between matches should keep them topped off. A caution, don't charge batteries when they are warm it confuses smart chargers.
First is planning to get at least 10 matches in qualifying at each event, so if one goes all the way to finals, you might have to play as many as 19 matches in a weekend.