Does a LiFe battery look like a LiPo?When I do all fire testing I use a 100ms current pulse. (Q2G2 came out as 333mA)
A 2Ah capacity battery is more than enough. Assume that on average the load pulls 10A for 5 seconds. 2Amp-hour * 3600 seconds/hour/50 Amp-seconds = 144 launches.
Capacity is only loosely related to internal resistance. I have a 1 Ohm 25W resistor that is very handy for testing. Connect in place of igniter and measure the voltage across it. A good 12V system should manage 10V or better.
I have a 4.5Ah SLA battery that I use but I am on the lookout for a 4 cell LiFe battery of around 1Ah capacity.