Battery boomdocking dlemma.

[rbpru]

We have been considering doing a bit of boon docking. We have noticed several opportunities in our travels.

Unfortunately we barely get two days use out of our battery even though we have installed LED lights, and the frig, water heater, run on propane. The furnace is a big draw so we seldom use it, that leaves only the pump and phantom loads. I even shut off the TV booster and pulled the fuse for the radio/DVD player.

According to the battery information I have gathered, my 100 A/hr. battery would like to be charged at C/10 or 10amps for 10 hours.

So, I have three questions.

1. If the battery is half depleted, does it only take 5 hrs. at 10 amps?
2. If I park in the sun with solar panels on the roof, the TT heats up like an oven. If I park in the shade the solar panel lose their output; unless I move the panels off the TT roof to the ground. But, then I must leave them unattended while we tour the local tourist traps. What am I missing here?
3. I could buy a small generator to provide the 10 amp charge but then I would have to leave it running unattended for 10 hours when I am not there or run it at night when we are in camp. These sound like poor ideas.

At this point I am curious what others do to keep their battery charged up.

[bobndot]

Ron3rd wrote:
Personally, I would not boondock with a single battery. Add a second one, they're cheap.

x2 for sure .

I carry 4 , one on the tongue, one agm inside the TT for the tv/sat system off a PSW inverter. Doing that saves the coach battery for lights, water pump and fridge circuit board.

I have 2 more grp 31's in the truck bed mounted in front of the wheel wells. They can stay charged while a drive around . They are always ready to go if i should need them. You can buy a Lance truck camper bed mounted connector using 8ga wire. It charges the batteries in the bed very well.

I use a Honda 2k for an hour or two each day or so. I run a 3 stage charger for the inside AGM and the OEM wfco converter which i know is not the best, but it does what i need it to do. I bring the batts back up to about 80% or so and that's ok for my use.

Recently i bought the new harbor freight 100w solar set up. I only tried it at home to test it out and it charges up the 50% depleted coach battery very well. I know its not the best system, but it does charge the battery and it was $139 with a controller. I plan to use it on the ground,moving it around to follow the sun. I park in the woods with many trees.

[Ron3rd]

Personally, I would not boondock with a single battery. Add a second one, they're cheap.

[bobndot]

See how your 12v battery power is being used . EX: northern breeze fans use power when off. :S


RV current readings

[ktmrfs]

Artum Snowbird wrote:
With a Honda 2K generator you would likely be able to run it for one hour a day and your battery would charge to 80%, then drop to 50% overnight. Remember, your battery charger that is built in is very capable of providing 30 to 45 amps in one hour, and your battery is capable of taking that.

the battery charger in a trailer is capable of 40 amps, however if it is a WFCO panel, the likelyhood of every getting more than 10 maybe 15 amps is very close to Zero. Been there, done that, about the only way it occurs is if you have a large battery bank, 4 batteries or more, the charger within a foot or so of the bank, and connected with #0 or larger wire, and a bank discharged below 50 percent.

Otherwise by it's design it will rarely if ever go into bulk mode charging, and be stuck with a 13.6V output giving around 10 amps. WFCO even admits that. the design looks at voltage at the converter AFTER it tries to put 40A into the bank. in virtually all cases the voltage then is high enough to tell it to drop into maintain mode.

PD Iota and others look at battery voltage BEFORE applying power and if it low, they go into boost mode. Much better for boondockers.

Every time we boondock with other campers around someone is running the honda generator most of the day and has a still discharged battery. they ask how we do it. I walk over with a clamp on ammeter, look at the panel, it's a WFCO, and I show them they are only getting 10A or so not the 50 claimed. I say we will check in the morning with a dead battery. same thing, around 10 maybe 15 amps max, and within an hour or so, down below 10A. Takes forever to charge that way. Once educated, they put a PD drop in replacement on the "to do list".

If you don't boondock, nothing wrong with the WFCO converter, quite, reliable etc. just not a good choice for boondocking

[time2roll]

First get a second battery. If the solar is not really working for you the get a generator. Probably need to upgrade the converter to get a faster charge in two or three hours while in camp.

[2oldman]

pianotuna wrote:
Any idea of the cost per day for fuel when the air is needed?Any success with running the air from the solar?

In 90F running about 8 hours/day I'd say it's around $5/day.

Yes. Solar helps, but there's no running directly from solar. When the cat needs cooling in the coach I'll run the air driving down the road. Pulls about 24a @ 50v. Solar does about 1/2 that.

[DownTheAvenue]

Turn off the condensation eliminator on your Dometic refrigerator. It slightly warms the the frame between the freezer and refrigerator sections and draws a lot of 12 volt power.

[pira114]

Not that any of the advice is bad, but it's really not that hard. I boondock a lot. '87 Wilderness with all original lights and inefficient appliances. One deep cycle marine battery. I charge it on a gen for about an hour a day. Maybe two, if I have no neighbors and no where to go. I never worry about running out of battery. With two 30lb propane tanks, I can go two weeks. Water is what I have to resupply.

[corvettekent]

We camp in the sun and leave the vents and windows open. We boondocked for 100 days this winter and the solar kept the batteries charged.

[pianotuna]

Hi,

For your upgrade, consider one of the hybrid inverter chargers from Victron, Outback, or Magnum. They all allow charging at over 100 amps.

bartlettj wrote:
Finally, now I bought a Champion 3100 generator so I can charge batteries and run AC if I want to. I only use it sparingly, but it definitely extends my camp time. I've given the group 24's to someone who needed them. I'll probably upgrade my charger so I don't have to run the generator very long to bring the batteries up. The generator weighs slightly less than the pair of group 24 batteries.

[profdant139]

If you have been letting your batteries run down below 12.1 volts, they might be damaged. We often get four days from one group 31 battery, without charging it at all. With a 120 watt portable solar panel, it lasts a week or more.

Please don't ask how I learned that improper battery maintenance kills the batteries. Very expensive lesson. Sigh.

[Dennis12]

Buy a Honda 3000 inverter. Problem solved. If you maintain it it will out live you. Money well spent

[pianotuna]

Hi 2oldman,

Any idea of the cost per day for fuel when the air is needed?

Any success with running the air from the solar?

2oldman wrote:
I camp in the sun and use 2 Honda generators to run air.

[bartlettj]

I've done a few different things over the years to extend my boondocking stay time. I almost always boondock in the forest so solar is out for me. The first thing I did was to replace my pair of group 24 batteries with a pair of GC2 golf cart batteries. This gave me about 220AH capacity with much deeper non-destruct deep cycle capability than the marine/RV group 24's.

However, I didn't discard the group 24 batteries because they were still good, so I would charge them at home and haul them with me well strapped down in the back of my tow vehicle. Then I had another set of batteries I could swap in when the main batteries ran out.

Finally, now I bought a Champion 3100 generator so I can charge batteries and run AC if I want to. I only use it sparingly, but it definitely extends my camp time. I've given the group 24's to someone who needed them. I'll probably upgrade my charger so I don't have to run the generator very long to bring the batteries up. The generator weighs slightly less than the pair of group 24 batteries.

[Artum_Snowbird]

With a Honda 2K generator you would likely be able to run it for one hour a day and your battery would charge to 80%, then drop to 50% overnight. Remember, your battery charger that is built in is very capable of providing 30 to 45 amps in one hour, and your battery is capable of taking that.