Question about battery charger and RV battery for a 5er

Keep in mind that those incandescent automotive bulbs will draw 1AMP EACH from your battery...

Those ceiling light fixtures have two of those bulbs in them... You can have as much 12AMPS or more being drawn rather quick with just the lights being on...

Thats like leaving your headlights on for several hours in your truck...

It takes some planning to run off your batteries and the first thing everyone does is get some LED lights running just for camping off the power grid... A LED light is a 80% current savings for each 12VDC Incandescent automotive bulb.

Our battery bank is 255AHs capacity and we can run just about everything we want to run except the air conditioner and the microwave unit. We run a bunch of 120VAC low wattage items from a 600WATT PSW Inverter and the other items are direct connected to the 12VDC batteries.

Then our game plan is only run the battery down to its 50% charge state then charge it back up the next morning when allowed to run our portable generator to the 90% charge state so we can do this all over again the next day night run off the batteries. We have the 2KW Honda generator and connect the trailer shore power cable directly to the generator which will run the on-board converter/charger using smart mode charging to recharge our battery bank back up to their 90% charge state in as little as three hours of generator run time.

We never had much luck just showing up at the camp site and making it through the night without planning...

We also never had good luck unless our battery bank was charged up to their 90% charge state before running them all night. Usually got dark around 10PM each night.

Two of those 6VDC golf cart batteries will give you between 200 and 225AHs capacity depending on which ones you purchase.

The SAMs CLUB batteries will cost around $90 each plus a couple of dead batteries... Ask them first if they will take two 12VDC dead batteries - bet they will...

We tried all of these games in our back yard until we got what we wanted to before going camping off the power grid...

Roy ken

Your main draws are not the water pump or lights or slide, but most likely the control circuitry for the fridge and the power needed for the propane and CO detectors and so forth. If you're camping somewhere cold and using the furnace, that is a quite significant electric power consumer.

That battery charger should work, but your built-in converter would probably be at least as effective (and probably more so).

It's impossible to give much accurate advice without a better handle on what your actual electrical use is, including the parasitic sorts of drains. That said, I might venture to guestimate that the battery you link to would be good for about a day of camping if fully charged without getting too deeply discharged, but almost certainly not a few days. Even a pair of golf cart batteries would probably be pretty tight for 3-4 days with no charging. A solar setup, even a rather modest one, would be a big help here. ("Rather modest" as in maybe a couple hundred watts, not as in 10-20 watts!)

Don't waste your money on that dinky little 12 amp charger, your RV converter is probably substantially larger.

Why waste $100 on a 12v battery that you intend to replace?

Take the charger money, the 12v battery money, and go to Sam's Club and buy the two GC2 that you really want.

cmb wrote:

jayspi wrote:
We have one 12v marine deep cycle battery in our 5th wheel and we just realized it's pretty much shot. We boondocked for the first time the other night and the battery was dead by the next morning, even though we only used it to run lights for a few minutes and to switch on the water pump when we needed it.

Hmmm, that seems excessive. Are you using incandescent lights? If you turn every battery operated device off, how much current is drawn from the battery? (Hint: It should be zero.)

I know embarrassingly little about all of this, but I'm pretty sure they're incandescent lights. They're the ones that came with the RV and they do run very hot.

Also not sure how much current is drawn from the battery, but we don't run anything that should draw current except the lights and water pump. I also think the fridge uses a little when it fires the propane, but that should be minimal.

That said, we've known for a while that the battery is shot, I just didn't realize how bad it was until we boondocked for the first time. The first time we used it to bring out the slide it dropped to 2/3 power immediately. Also, a circuit breaker tripped while we were gone the other day and when we got back the battery was dead. We were just gone a few hours, and we only had a couple of lights on. Point is, I don't think something is draining it, I think it's just shot. The previous owner did 0 maintenance to this RV.

jayspi wrote:
We have one 12v marine deep cycle battery in our 5th wheel and we just realized it's pretty much shot. We boondocked for the first time the other night and the battery was dead by the next morning, even though we only used it to run lights for a few minutes and to switch on the water pump when we needed it.

Hmmm, that seems excessive. Are you using incandescent lights? If you turn every battery operated device off, how much current is drawn from the battery? (Hint: It should be zero.)