Power Supply

[jacqueg]

I have a single 200 ah LiFePo battery that I recharge with a van roof-mounted 286w solar panel. Although I haven't really tested it, I believe my system could run my 12v referigerator for 3, possibly 4, winter/sunless/coolish days. So, Tony, I think what you are asking for would not be achievable without more batteries. Which would weigh more and cost more than carrying some solar panels. However, a smallish gas generator would probably work in your situation.

No, I don't like gas generators either. I lost my 2000w Honda in the Great Van Heist of 2021, and have so far managed to not replace it. (I did buy a 1000w Jackery, because I can replenish it from any shore power source.) But without solar panels, I don't know how you would recharge your house batteries without a gas generator, because it's pretty hard to unplug a house battery and carry it into a Starbucks!

 

[abnorm]

I went to a pot luck today, quite a few of the people were talking about all the electrical issues they are having.

It was JimInDenver waxing poetic about his workload.....and Scott and Mark getting advice

 

[mpruet]

Just for comparison. I have a RV built on a RAM Promaster. It has 2 100 AMP hour AGM batteries with 200 watts solar on the roof and 100 watt solar portable panel. I also have a 4.3 cu ft. fridge. After the sun goes down the only thing I have running on the batteries is the fridge. I’m diabetic and use insulin so the fridge must always be able to run.
At sundown my batteries are fully charged with voltage at 12.7. By morning time I’m down to 12.2 Volts, which is basically 50% depleated. Since these are AGM, I try to avoid ever going lower than 50%. Basically this means my fridge is consuming 100 AMP Hours over night.

Now I realize that you’re talking lithium and not AGM, but still I’d suspect that you’d have trouble getting three days out of the system, especially if you are not really well insulated.

 

[bullfrog !]

^^^is the 4.3 cubic foot fridge a 12 volt DC or a 120 volt AC running off what size inverter as some people do? So about 8 to 10 amp draw over 12 hours? So what do you charge with after a few cloudy days?

 

[VanFan]

...it's pretty hard to unplug a house battery and carry it into a Starbucks!

That's one reason I am wondering whether two small power stations would be a good option, leaving one in the van to run the fridge while recharging the other with a portable solar panel, in a public space, or (gasp!) a motel room.

Tony: You mentioned that you want to avoid multiple power stations. May I ask what you are thinking the downside(s) is/are? (I am following this thread with interest as I imagine possibilities for our next van.)

 

[mpruet]

^^^is the 4.3 cubic foot fridge a 12 volt DC or a 120 volt AC running off what size inverter as some people do? So about 8 to 10 amp draw over 12 hours? So what do you charge with after a few cloudy days?

It’s a 12 volt DC compressor fridge. i can recharge from my solar, generator, or my alternator.

 

[Tony's Dream]

I went to a pot luck today, quite a few of the people were talking about all the electrical issues they are having. They are the ones with big battery banks and lots of solar panels. Is it really making their life easier? No, not really…

That is what I am concerned about as well. You can overspend and end up right where you started.

 

[Tony's Dream]

Thanks everyone for for you input. I think I will buy the fridge first, as suggested, and build from there.

 

[user 22017]

>>>> When you are plugged into 120 volt AC grid power a built in converter supplies the 12 volt power and charges your “house” or “trailer” battery or batteries mounted usually on the tongue of the trailer.

Can the batteries be locked to the tongue? Can AGM's be stored inside the trailer? Just lead acid have off gassing?

>>>> Depending on how your tow vehicle and trailer are wired some tow vehicles supply 12 volt DC power to the trailer house batteries while the tow vehicle is running as well.

That sounds nifty. Is it complicated?

>>>Solar systems can be integrated or independent of the factory system. If your trailer came wired for solar with a factory plug in for solar panels they when plugged in will charge the batteries on the tongue usually.

I have portable panels. It seems some nomads want as much power as they can get. I want to learn to live with as little power as possible. I do have a weakness, though... gaming. Might have to limit my gaming to when I am at a pay spot.

>>>>Batteries are expensive and if you boondock using the factory appliances you will find in most cases you will go below 50% capacity ( which can shorten the life of or damage the AGM battery ) of an AGM battery in just a few days or less without additional charging.

Not using the frig that came with the trailer. It's my food pantry now. What other factory appliances that use power are there? Lights don't use much (gotta swap them to LED). The on-demand hot water... that won't be used much. Not gonna use the furnace. What am I forgetting?

>>>>Running a small cheap generator or adding an expensive solar system both work but new battery technology should be considered if you plan on living on the road full time for 5 or 10 years. I have figured out how to supplement my old AGM batteries using an EcoFlo Delta Il and a generator/solar to keep from having to convert to an independent LifePO4 battery system for now but converting should be considered if you plan on living off grid for long periods of time.

What is the "new battery technology"? You mean lithium? I bought a lithium power station and 220 watt solar panels. I don't want any more lithium because of it's environmental impact.

Thanks a million, Bullfrog

 

[bullfrog !]

You can buy locking mounts, box or even have a box built. I have stored AGM batteries inside but usually not the living area and usually enclosed. It is too easy to short them out if terminals are not covered. Usually people that expand their battery bank use a storage compartment accessible via an outside locking door. Mine have been in a box on the tongue for years with no problem.
If you have a seven pin trailer plug with a 12 volt DC wire that is 10 gauge on the trailer and the tow vehicle it probably is already there but you probably should have someone check the wiring is correct for your system.
Fans and any 12 volt DC devices you leave plugged in 24/7. If you use an inverter disconnect it when not in use. LEDs really make a difference so do that.
Yes and what ever they come up with next!

 

[onethoughtatatime]

Just for comparison. I have a RV built on a RAM Promaster. It has 2 100 AMP hour AGM batteries with 200 watts solar on the roof and 100 watt solar portable panel. I also have a 4.3 cu ft. fridge. After the sun goes down the only thing I have running on the batteries is the fridge. I’m diabetic and use insulin so the fridge must always be able to run.
At sundown my batteries are fully charged with voltage at 12.7. By morning time I’m down to 12.2 Volts, which is basically 50% depleated. Since these are AGM, I try to avoid ever going lower than 50%. Basically this means my fridge is consuming 100 AMP Hours over night.

Now I realize that you’re talking lithium and not AGM, but still I’d suspect that you’d have trouble getting three days out of the system, especially if you are not really well insulated.

That is a big fridge. Years ago, I mentioned here before, I did a few tests with different sized fridges and my nickel iron batteries and 190w of solar. The 60ltr normally opening fridge (half 4.3cuft?) was really trickiest to cool in summer. The cold kept flopping out the door. The 40ltr chest fridges Engel and Waeco were very similar in their usage and it seemed at the time much more efficient. Maybe twice as much at total guess.

I wonder, if you fill any unused space with jugs of water might help with the efficiency of such a large fridge? It makes for less cooling of air inside. Might be worth a try especially if it's a normally opening one.

 

[RonDean]

I can remember reading something to the effect that keeping your frig full did indeed help it maintain a constant temp. I have a smaller chest type so don't worry about it quite so much.