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How much battery needed for fans and pump? Answered

I have 2 12v fans, 1.2 amps each, and a pump, also 12v, 2.5 amps, all of which I want to run off of a single battery for about 40 or more hours. How much battery do I need? Thanks!



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9 years ago

So you want to know how much of a battery to run 4.9 amps for 40 hrs.
Recently some one said a top, car battery could do 80 Amp Hrs.

That suggests about 16 hrs per battery and 3 car batteries
to run two fans and a pump over 40 hours.

You do understand as the battery discharges the voltage falls
to 10.5 VDC at 100% discharge.
Your fans and pump will slow down with battery discharge.

see TimAnderson's ible
Easy Test of Battery Amp-Hours Capacity
for more info.