Battery bank voltage: 24v or 36v

[davidsuzuki256]

Hello,

I have been contemplating on living alone in wilderness, starting my journey to a spiritual enlightenment. The main purpose of the solar system is mainly to run three appliances: a simple LED light to read religious scriptures, a small fridge (2.7 cu. ft.) and a small window air conditioner (500w). My question is whether the battery bank voltage of the small shack to be 24v or 36v for this system?

The charge controller I use currently is a PWM (20a) and the battery bank AH is around 150.

David

[organic farmer]

Lose the refrigerator and the A/C.

Seriously I have seen people go through the math hundreds of times.

I live off-grid. I live in an area where there are a lot of us off-grid [I live in Maine]. Trying to run a freon compressor [like A/C or a refrigerator] is too much wattage. Unless you are looking at spending over $20k.

[jflorey2]

I have been contemplating on living alone in wilderness, starting my journey to a spiritual enlightenment. The main purpose of the solar system is mainly to run three appliances: a simple LED light to read religious scriptures, a small fridge (2.7 cu. ft.) and a small window air conditioner (500w). My question is whether the battery bank voltage of the small shack to be 24v or 36v for this system?

Like the previous poster said, ditch the A/C. If you want refrig then you will probably have to buy new; a Sundanzer is around $500-$1000 and will run on 24V. Sunfrosts are pretty efficient as well and run around the same prices. They are as small as 4 cu ft. You will save money doing that, rather than trying to build a system big enough to power your inefficient fridge.

24V is MUCH easier to work with than 36V. More available for that voltage.

[Logan5]

Dometic and nor cold make some smaller units around 500 bucks. Air conditioning will cost way too much hauling several tons of lead acid batteries deep into the wilderness, Expensive study of man made religions.

[davidsuzuki256]

Thanks for all the replies. Sorry if this has been asked before but is it how much risk is there in trying to running a small fridge off a Modified Sine Wave inverter?

The SunDaner brand looks promising with the option of running it under both 12 and 24v ..

[Logan5]

no problem if you don't mind replacing the refrigeration unit ever few months. Unless you are using a modified chest freezer and a pure sine inverter, you will have great trouble with this project. Better yet get the DC chest style unit. Off grid life requires big changes, especially how we use electricity and water. Many things can be done incorrectly costing big money in the long run. reduce your demands, the less you need the more you will have. Get out of the 12 volt box. Refrigeration requires at least 24 volts especially if you insist on using an inverter.

[inetdog]

Thanks for all the replies. Sorry if this has been asked before but is it how much risk is there in trying to running a small fridge off a Modified Sine Wave inverter?

The SunDaner brand looks promising with the option of running it under both 12 and 24v ..

AC compressor motors in refrigerators will be noisier, will run hotter, and reach their end of life sooner with MSW instead of PSW. There may also be some problems starting them.
DC motors (or motor controllers) avoid that problem.
Depending on your location a small swamp cooler may keep the inside of a shack perfectly comfortable for only the power drain of a small water circulating ;pump and a small fan. If your summers are very humid, chances are a swamp cooler will not be satisfactory.
Either way good insulation and good air infiltration barriers would be critical to economical comfort.

[Sunking]

Forget air conditioning, never going to happen. and pray for cool weather. That is your only option. Do not expect an answer from heaven when you are in Hell burning up. God has no mercy for fools.

[jflorey2]

Thanks for all the replies. Sorry if this has been asked before but is it how much risk is there in trying to running a small fridge off a Modified Sine Wave inverter?

OK. Drop the idea of using your cheap small fridge. You will likely destroy it with an MSW inverter, and to run it with a PSW, you'll have to add thousands of $$ of battery and solar panels to your project to deal with the inefficiency.