PR1aW Battery Life at 100 mW

This is a re-post from another thread, but it really belongs here.

Actually, I realized that by doing a little algebra with the stated battery times with and without the radio, I can arrive at the answer.

Battery life for 2700 mAh NiMH batteries with 1 pulse/minute at -20C (-4F):

No Radio: 57h (from manual)
Radio at 10 mW: 28h (from manual)
Radio at 25 mW: 16h
Radio at 50 mW: 9h
Radio at 100 mW: 5h

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.