How much battery for several days of basic use?

[curmudgeon59]

We recently purchased an 07 29' 5th wheel trailer, and I'm trying to evaluate what I may want to upgrade or change. One thing I want to figure out is how much battery I need/want. The first owners apparently added a second battery, and then the next ones added a 3rd. But nobody bothered to swap out the lights for LEDs

I expect to be staying a fair bit in state/national parks where we may not have hookups, and so I'd like to figure out an appropriate battery/lighting/charging situation. We don't figure to watch TV or use the microwave, so I think my electrical needs would be pretty much just lights, water pump, and landing jacks/slideout. I could add solar (and might), but some of those campsites are pretty shaded.

Could I expect to get away with, say, 2 6V batteries for short showers, washing up, and several hours per night of led light usage for 3-4 day stays? I'm sure some of this will become quickly apparent with experience, but I'm trying to set my expectations.

[Skip426]

Welcome to iRV2.

Try this site for info on your 12 volt usage . Running the furnace is the biggest draw on your 12 volt system , unless you have an inverter to use 120 volt appliances.

The 12volt Side of Life (Part 1)

[twinboat]

I think you will get by with 2, 6 volt batteries.
I get a bit more then a day on 2 of them with some TV watching and morning coffee maker.

If you do all the heavy current things while hooked to the running truck, and then only use the batteries for some lights and water pump, you should do fine.

You can buy 2, 6 volt batteries and test it out at home. If the batteries drop much below 12 volts, you can add another pair.

Its important to start your trip with full charged batteries.

[snowman1]

Pick up one of the quiet little 2000 watt inverter generators from Honda or Yamaha and you'll be good to go until you have a better idea of your electrical usage. There are so many variables here it's impossible to guesstimate. I've got 4 six volt Crown deep cycle batteries rated at 260 amp/hr each giving us in theory a 520 amp/hr battery bank but in reality a 260 amp/hr bank at 50% SOC. Going below that level kills batteries. We've got 640 watts of solar panels laying on top of this thing and we still need to run the genny in the morning if the furnace was running during the night or even during the day if the sun isn't beating down on us.

On just this site alone you can spend hours reading about electrical usage while dry camping but at the end of the day you want options. These little genny's are quiet as a church mouse, only weigh about 50 pounds, don't use much fuel and will run everything in your 5th wheel except the A/C. And if you want, you can parallel them with a second one which will let you power one air conditioner easily. They're Forest Service legal and won't upset your neighbors because they'll probably have one also. Just be sure to chain it up because they're known to sprout legs and run off.

[MSHappyCampers]

Hi ! Welcome to IRV2! We're sure glad you joined the gang!

Sorry, we've never done any boondocking!

Good luck, happy trails, and God bless!

[Finance]

We had a similar rig before and similar use to what you describe. Two nights with moderate furnace use or four warm nights was typical with two GC batteries.

[egwilly]

It will help if you install a Trimetric Battery Monitor so you can keep an eye on the voltages and amp draw, before the batteries are damaged by using them below 70% constantly.
They need to be recharged when boondocking either with a generator or solar.

[curmudgeon59]

Thanks for the responses. I'm working my way through a variety of things getting to know the trailer and getting things set up. Adding a more detailed battery monitor may be helpful in the future, but I'll start with basics. We took the trailer out for a local one-night stay to go over things (it's stored about 25 miles away). After a night on shore power (3-stage converter), I took a SG tester to each of the cells. Turns out one battery was just dead weight, one had 5 of 6 cells OK, and one (5-year old 12V marine) was doing the work.

I think I'll start fresh (will need new battery boxes) and put in the two GC2s. If I find we need more power capacity, then solar or one of the little quiet generators. Are the ~2000 watt generators about optimal for charging batteries through a standard WFCO converter? Would smaller (1000w) charge almost as fast? I'm trying to stay on a weight (and cost) diet with the rig, so only adding the most useful upgrades.

[twinboat]

A 1000 watt generator will give you about 7 amps of 120 volt power. They are never actually 1000 watts.
It may be close to the amp draw that a 55 amp converters needs, under full load.

Check the specs for the amp or watt draw of your converter. As long as the generator can cover the load, either one will charge your batteries in the same time.

[kellylipp]

And if you boondock a lot then think solar. That way you don't have to listen to your generator!

A 400W solar system will cost less than $1000 and will keep a dual battery system topped off nicely (unless you live in Oregon or someplace else with little sun).

egwilly steered you right: start with a meter to see what you actually use and then from there. If you purchase the Bogart you can add their charge controller and four 100W panels (or more) later to keep yourself charged.

The link in my signature is a blog where I discuss a number of solar installs I've done on my rigs. Should get an idea about what to do from there. If you're in the hood I'm happy to help.

[Dranoel]

Buy a small inverter generator. You will appreciate it if you plan any boondocking even if you have solar because the sun is unreliable. After you have some experience you can decide if more batteries and/or solar make sense for your type of camping.

[OLYLEN]

All reasonable above. I'll add one more's if you are going the Gen route I would go with one of the QUIET 2300 watt gens so you can run A/C if needed.

LEN