NGC Battery back-up

[Roebling3]

I'd like to ask for opinions on suppliers for a packaged system similar to trailers & self contained RV's. Power would be needed 24/7, for medical reasons.

What may be the best way toward storing electrical energy in a 3 ton van? Aprox. 1200 cu. ft. insulated.

At this time I don't yet know the total energy requirement.
i.e.: small refrigerator, air conditioner, temp. control 50 to 80 deg. F, electric wheel chair.

The stored electrical energy would be used for cooling/heating over several days/weeks at a time.

Might it be better to use a contemporary electric automotive charge & recharge system, scaled for the purpose? Re-charge at charging stations?

Are there suppliers for a packaged system? Thank you for sharing your views. PM's welcomed.  R3~

[Kiwi_Roy]

I have worked on projects where energy is stored in tanks, surplus electricity is run through an electrochemical cell where it converts a chemical from one form to another. This has the advantage that it can be scaled up by adding tanks.
When the energy is required the liquid is run the other way and electricity is produced.

Visualize it like a lead acid battery not just constrained to how much energy can be crammed into the battery but with an unlimited supply of activated acid.

Of course there are other batteries like Ballard where the energy is stored as Hydrogen gas under high pressure. Methanol is another liquid that can be converted to electricity in a fuel cell.

[Guzzistajohn]

In a former job I was a Rebab tech, so I set up power mobility equipment. Most power wheelchair manufacturers have kits for backup power to run ventilators and oral suction machines and so forth. They’re really nothing more than a shelf or bracket to hold a Couple of Gell cell batts and a charger. One time I rigged a wagon with 2 22 NF batts and charger to run a heated aerosol generator (HAG) for an Amish kid, his family would pull it down the road to the neighbors house to charge in the daytime. That was a fun job from time to time 👍

[not-fishing]

Sounds like the amount of power you're going to need will be to expensive in batteries alone.

A Honda suitcase generator might be your best solution.

[SeanF]

I think a quiet Honda generator with a few gallons of gas would be the most cost-effective solution.

Calculate how much power you'll be consuming at any one time and size your generator based on that (and add a 10% margin for appliance startups or other surges). Climate control will likely be the biggest consumer.

[rocker59]

RVs use a couple of deep cycle batteries, but they don't power much and don't last long.  They're not intended to support the vehicle.

For power, they use an onboard generator.  Honda, Generac, Onan, are the three popular choices.

You can get the generators in Gas, Diesel, and LP versions, depending upon the easiest fuel source for you and your RV.

[acguzzi]

I agree with the generator option, batteries are cool and quiet but don't store much energy, if you want temperature control for a few days then you need tens of kWhr which will cost tens of k$ and are huge, running your engine to recharge batteries is also horribly inefficient, get a generator. Fuel cells are also very expensive.

[Roebling3]

Thank you everyone. As always; There's good answers to every question right here.  R3~

[Wayne Orwig]

At this time I don't yet know the total energy requirement.
i.e.: small refrigerator, air conditioner, temp. control 50 to 80 deg. F, electric wheel chair.
The stored electrical energy would be used for cooling/heating over several days/weeks at a time.

Generally speaking, there is not enough roof on a van to gather the power needed to operate an AC, or operate electric heat.

Let us say you have room for 600 watts in panels, and I'm not sure you would. If you have a good open sky for 8 hours, so maybe you get 4800 watt hours per day. A BIG 100AH lithium battery at $1000 holds about 1200watt hours. You need 4 of those. So you are over $6,000 for panels, controller and batteries. You can save money with lead acid, but need more batteries and space.

A small AC unit is maybe  1400 watts. Toss in the inverter and storage inefficiencies, and you can maybe run the AC for 3 hours, maybe. Electric heat is a big energy suck also.

Just running a small fridge and charging a device like a wheel chair is much more practical. A small fridge may need 240 watts (wild guess) and runs maybe 30% of the time (another guess). Or just under 2000 watt hours per day. So that is more practical.

I have two LARGE lead acids in my RV. They run lights and the furnace fan. The rest is run from propane or generator.

A generator is a lot more flexible at running everything.

[Rick in WNY]

Couple years ago I bought a 38 foot "park model" camper... cheap.

I't called this because the nose is all windows, has a sliding glass main door, and is set up to run off grid power.

I do have 2x 12v deep cycle batts on it with 200 watts of solar to charge them. This is enough to run the electronic pest repellers and keep everything energized for the camera system. Yes, my camper has a security system, it's also a very nice game cam!

When I stay there, I use my 6kW propane generator. This was done instead of a solar/battery/fuel cell/ canned unicorn system on the recommendation of people who live in RVs for months at a time.

Generators are your friend, and propane ones are the cleanest and easiest to live with.

Good luck!