House battery charging options

[etrippe]

We are 4 months into our new travel trailer and having never owned one before I have some questions about battery charging. I was wondering if while camped, would plugging back into my running tow vehicle charge the battery? We don’t plan on any extended boondocking but for one or two times a year for maybe 5 days maximum. No ac, tv or microwave required. However our refrigerator is 12 volt and we have a max air fan that would be running all night possibly. Just looking at our options. Generator, solar or just run the car. Trailer has 1 12v. battery, and most likely low quality.

[Grit_dog]

etrippe wrote:
We are 4 months into our new travel trailer and having never owned one before I have some questions about battery charging. I was wondering if while camped, would plugging back into my running tow vehicle charge the battery? We don’t plan on any extended boondocking but for one or two times a year for maybe 5 days maximum. No ac, tv or microwave required. However our refrigerator is 12 volt and we have a max air fan that would be running all night possibly. Just looking at our options. Generator, solar or just run the car. Trailer has 1 12v. battery, and most likely low quality.

You haven’t been back to post how your test went, but a DC compressor fridge and 1 battery sounds like about the worst possible setup for boondocking.
This model appears to have been made with only fhu in mind.
Good luck. I suspect you’ll need to do a couple different things to make this work for extended use without hookups.

[AllegroD]

Your test is a good idea but take into consideration that if you run the furnace and fridge during the day, the furnace and/or fridge may not run as often as during a cool/cold night. Many places have quiet hours 10-6 or longer. You will likely find that a single 12v (wet) battery will likely not get you through the night. I think the suggested 6v GC is a good consideration. Another consideration might be multiple lithium. You get to use most of the AH in them, say down to 5-10%.

[dieseltruckdriv]

I have about $500 to $550 in my 420 watt solar system. I have two Honda EU2000i generators that haven't been run in two years except to exercise them.

We are on two weeks with no hookups and I am listening to it rain right now.

I love the silence of solar and not having to worry about my generators getting stolen. It is hard to put a price on happiness.

Everyone is different, no on way is right for everyone.

[Dirtclods]

etrippe wrote:
We are 4 months into our new travel trailer and having never owned one before I have some questions about battery charging. I was wondering if while camped, would plugging back into my running tow vehicle charge the battery? We don’t plan on any extended boondocking but for one or two times a year for maybe 5 days maximum. No ac, tv or microwave required. However our refrigerator is 12 volt and we have a max air fan that would be running all night possibly. Just looking at our options. Generator, solar or just run the car. Trailer has 1 12v. battery, and most likely low quality.

This little set up will fit your needs

https://www.harborfreight.com/100-watt-solar-panel-kit-63585.html?_br_psugg_q=solor+panel+kit

[theoldwizard1]

1320Fastback wrote:
Of all the options I would get a small 2K watt Inverter Generator and run it during the day time to top off the batteries.

Depending on the frequency of usage, I still believe a good 40A - 60A DC-DC charger and using the tow vehicle is a reasonable solution to recharging a house battery.

[1320Fastback]

Of all the options I would get a small 2K watt Inverter Generator and run it during the day time to top off the batteries.

[enblethen]

2,5 amps to maintain temperature, 8-9 amps to cool down'
Going to need more then standard amount of batteries for this compressor style 12 volt DC refer.

[etrippe]

enblethen wrote:
What is make and model of refer?

Ever Chill 10.7 cu.ft. WD-282fwdc b 6

I’ve disconnected the power and running the frig and fan at 50% using the battery as my power source. I will see how long the battery lasts. I won’t let it go down past 50%.

Any thoughts on how long it will last?

[Timmo_]

A very good practical solution is the charge the batteries each morning with a quality quiet generator such as Honda EU2000i.

https://powerequipment.honda.com/generators/models/eu2200i

Some people may think solar panels are better and more affordable, but if one does a breakeven analysis the cost savings for solar panels may never materialize for most of us. It depends on how many hours the generator is actually used each year.

Here is a link to Solar vs Honda financial breakeven analysis that will help determine which source of power is cost effective.



https://www.nroa2003.com/download/Miscellaneous/Cost_of_Solar_vs_Honda.xls

Of course the breakeven analysis for carbon emissions is a different story all together. At what point does the accumulated emissions from the generator's manufacture and operation match that of the solar panel emissions? If we take a page from the BEV's breakeven analysis, then it probably is several years away for heavy RV users and probably never for the occasional weekender.

[wing_zealot]

Get a small generator, it works day or night, whether the sun is shining or it's been rainy and overcast for a week. You can generally recharge your batteries enough in a few hours.

[theoldwizard1]

etrippe wrote:

I’m at home now so I will disconnect the trailer from shore power, turn on the fan and time it till the battery goes down to 1/2. Good idea, thanks

50% discharge will shorten the life f a lead acid battery.

Two 6V golf cart batteries have about 210Ah, much higher than any single 12V lead acid battery and more than most pairs of 12V batteries.

Buy the DC-DC charger. At 40A it will quickly recharge a battery bank faster than anything short of a 50A AC powered charger. Bonus, you can drive while driving !

[BFL13]

etrippe wrote:
Thanks all. The frig is all 12 volt, no propane or 120 volt. All I want to do is keep the battery charged for the frig, fan and some led lights over night. Solar sounds promising but what if it’s cloudy for a few of the days that we are dry camping?

I’m at home now so I will disconnect the trailer from shore power, turn on the fan and time it till the battery goes down to 1/2. Good idea, thanks

Rule of thumb is one battery a day using 50AH a day. So your 5 days off grid is going to need some work with only one battery!

If there is no furnace time but is a 12v fridge it should be the same, but if furnace too, you are in a world of hurt for 12v. You will for sure need a generator and recharge the batts you do get/can carry in that RV and will need a proper battery charging converter or charger to do that. Solar can help with that chore, but as you note, the sun might not come out when needed.

Forget about running the truck engine as a generator, that is just for a last ditch way to get some 12v to last a little longer.

[enblethen]

What is make and model of refer?

[etrippe]

Thanks all. The frig is all 12 volt, no propane or 120 volt. All I want to do is keep the battery charged for the frig, fan and some led lights over night. Solar sounds promising but what if it’s cloudy for a few of the days that we are dry camping?

I’m at home now so I will disconnect the trailer from shore power, turn on the fan and time it till the battery goes down to 1/2. Good idea, thanks