That's not enough battery life for comfortable buffer. And based on optimal condition new NiMH batteries too, no doubt. This and the other post about spotty wireless connection and attendant missed pulses make me glad we put in the big effort over three summers to put in buried dedicated wiring to all our timing locations (16 in all) spread over technical and speed courses. If we were doing lots of low-key club or recreational group events, I could see the wireless system as being worth it.