This weekend I bought a Rule 500 electric bilge pump, and a 12 V dry cell battery (instead of a lead-acid gel battery). The combination pumped out a 5 gallon bucket in about 40 seconds, so it seems to work fine. Advantages of the 12 V dry cell are that it cost only $11.00, it is lighter than the gel cell, and it doesn't need to be trickle-charged.

I just don't know how long it will keep pumping, relative to the heavier battery (I suspect it doesn't have as much "power"). Any electrical-engineer types have a feeling for how these two power sources compare?

Thanks!