Powering the House

[Deebow]

All who can help:

Here is the conundrum.

I have a 2 battery (this winter to be 3) house bank and 2 battery starting bank (I am the king of redundant systems). I also have a 1500 watt inverter that is run to the house bank. It seems like the dual voltage frig, when left on 12V direct at night on the hook or tied to the dock (no shorepower), runs the house bank to nothing overnight.

Would it be better to run the frig on the inverter with 120AC power versus the 12 V Direct that it is also wired to? Would the load be virtually the same?

My plan for next year at the lake is to hook it to the generator that will be my impromptu shore power and use that during high load times (using the microwave oven during meal prep for instance) and then let the inverter run it the rest of the evening.

Am I doing right here?

[DeepFrz]

You don't mention the amp. hr. capacity of your batteries but even so a 2 battery house bank is no where near enough to power a 12 volt refrigerator. Putting it on the inverter is just adding conversion losses to equation.

[delmarrey]

Sorry, but I can run my freezer two days on my two bank (group 24) batteries. You either have a high draw frig or low amp batteries.

Give us some numbers and make of frig.
What else are you running at night?
And no, the inverter will draw even more amps just keeping the unit warm.

You may need to get an amp meter to see where your power is going.

[DeepFrz]

Del, you must have a very efficient frig. and good batteries. That sure hasn't been my experience.

Of course my experience was in the Gulf of Mexico and Caribbean and you may be talking PNW, two very different experiences when it comes to refrigeration.

[Bash]

it's a simple matter to figure the system's needs if we know (1) how many amp hours the house bank stores, and (2) how many amp hours per day the fridge draws.

you should never run the house bank to nothing. Once it's expended 50% of the available amp hours, it should be recharged. To go lower than that is to cut battery life short. Figure this 50% point into your energy budget.

I agree that using the inverter will only aggravate the situation.

(By the way, my 2-battery house bank will run the system for two days without needing recharging, even in warm waters, but that's because I've got two 4-D AGM batteries that are rated at 210 Ah apiece.)

[matauwhi]

G'day, mates. It also would help to understand the size (cubic feet will do) of the frig or freezer system when having these discussions to help compare apples to apples. Also, what climate zone are you primarily boating/living in; tropics, subtropics, or 4 season. Cheers.