Depends on a lot of things, but . . .
When refrig and freezer are both running, they draw 12 DC amps, more or less. Depending on your thermostat settings, they should run about a third of the time, after they have reached temperature. 12 x 24 = 288, divided by 3 = 96 amps in every 24 hours. Round it up to 100 for good measure. We have 2 8D gel batteries with combined capacity of 450 amps. Cut that in half for usable capacity and you get 225 amps available every 24 hours, assuming a full recharge, which you dont ever get unless you are plugged in. So, that means about 100 amps for the fridge and freezer and 100 for everything else, at best. The bottom line is you need to run the generator for at least an hour in the evening and an hour in the morning on an extended trip when you are not plugged in. Or, if you leave the dock fully charged, you can skip the night gen run but you must run for 1 1/2 hours the next morning. Watch you battery volt meter. We have a digital, available from JSI and it is very good. Dont let the "at rest" reading go below 12 volts without recharging. At rest means that the DC amp meter is on 0. That only really gives you a rough measure of battery state but it seems to be close enough. If you wake up in the morning and the at rest reading is 11.9 or 11.8, start the generator right away. We've put a lot of thought into this and think we have a pretty good handle on it. We were going to get one of those expensive [$500] amp meters, but we have realized that all it would tell us is to run the generator in the morning and the evening. We do that anyway for airconditioning and hot water for showers and to make coffee, etc, so we just do it and saved the money. Any questions, please email me. bcavedo@srglaw.com
