Will solar panel keep batteries charged while running fridge

kohldad wrote:
It depends on the model and actual draw. Based on some numbers I have experienced with my 100 Watt MPT system and current draw for the fridge I found on line, here are my rough calculations.

Figuring 0.2A for the detectors and radio, that is 4.8A/hr per day.

Fridge draws 0.6A with flame and 0.2A without flame. Figuring flame will be on 50%, that is 0.6 * 12 + 0.2 * 12 = 7.2 + 2.4 = 9.6A/hr per day.

Total is only 14.4 A/hr per day.

A 55 watt panel should deliver at a minimum of 2A for 8 hrs and 0.5A for 4 hrs for a total of 18 A/hr per day.

Bottom line is the panel should keep the batteries topped off. With two batteries, you could handle 6 days without sun shine before the batteries will be pulled down to 50%. And for each day the sun is away, it will take about 3 days of charging to bring the batteries up.

I would recommend you invest in a battery monitor such as the trimetric so you will know the true status of the batteries. Otherwise, you will probably be running the generator to charge when you don't really need to be charging.

Excellent advice and accurate estimate for AH.... One more panel and battery would be very comfy.

Jim

Thanks for the great info. It will be nice to have a "cold one" waiting in the fridge after working the property.

my camper sits in a my driveway which has trees along the one side that blocks sun in afernoons. full sun maybe 6 hours per day. I have 2 100w panels and 2 27 series AGM batteries. I never plug the camper in while sitting at home. It sits all summer with refrigerator running on propane.

If you are running the fridge on LP, then a 55w panel and decent sun should be more than enough to keep the control circuitry running.... Now, of you were trying to run on electric, you would need a MUCH larger system, and a big battery bank to get you through the night....

It depends on the model and actual draw. Based on some numbers I have experienced with my 100 Watt MPT system and current draw for the fridge I found on line, here are my rough calculations.

Figuring 0.2A for the detectors and radio, that is 4.8A/hr per day.

Fridge draws 0.6A with flame and 0.2A without flame. Figuring flame will be on 50%, that is 0.6 * 12 + 0.2 * 12 = 7.2 + 2.4 = 9.6A/hr per day.

Total is only 14.4 A/hr per day.

A 55 watt panel should deliver at a minimum of 2A for 8 hrs and 0.5A for 4 hrs for a total of 18 A/hr per day.

Bottom line is the panel should keep the batteries topped off. With two batteries, you could handle 6 days without sun shine before the batteries will be pulled down to 50%. And for each day the sun is away, it will take about 3 days of charging to bring the batteries up.

I would recommend you invest in a battery monitor such as the trimetric so you will know the true status of the batteries. Otherwise, you will probably be running the generator to charge when you don't really need to be charging.

55 watts is plenty to keep the fridge running. Your propane detector and possibly radio will also draw a little but far less than the 55 watt panel supplies.

Thanks. Yes it will be on propane.

Fire Guard,

If you run the fridge on propane, yes, the 55 watt panel will be enough to keep it running.

I'll check tomorrow.
Even if the batteries didn't stay fully charged, as long as the fridge stayed cold by using both battery capacity and recharging from solar I would be ok as I could top them off.

Highly doubtful.

What's the amp draw of the fridge on DC?