Thanks, Brian. +t That was the information that I was remembering, but I remembered it wrong. So, you need a 750 mA capability, but only to handle the peaks and you need less than 300 mA average. So, that does work out to about 24 hours for a fully charged, new battery pack like this. That would work out great because you could recharge over night off of a big battery that you leave back at the car... or even the car battery if it's in good shape.