Re: Using 7.2v charger as BackupBattery
 

In the rule book there is a rule about using a different backup battery as long as it was a 7.2 volt, that means you can if possible, grab a Vex battery, which is 7.2, but has 2000 mAh, instead of the measly 600 mAh that comes in the standard battery pack supplied by FIRST.

There are also standard RC car batteries that run at 7.2 Volts, which would allow you to do the same thing.

Another option is looking for the chart to make a backup charger from the 12 volt battery, however so far my team has decided not do this as we are already abusing our 12 volt battery.