Community Forums

HobieBaxter · 04-10-2021, 10:32 PM

Is it possible to use a standard 12v battery charger to directly charge a bank of 6v batteries (configured in series to deliver 12v to the the coach)? Our rented storage provides a GFCI 20 amp service that trips when plugged into our Newmar Kountry Star. The Newmar forum states this isn’t unusual. We are looking for a work around to keep the batteries charged and inverter working to run the fridge in between trips without depending on the generator. I’d plug the fridge directly into the GFCI but the cord is hidden behind a cabinet. TIA

HarryStone · 04-10-2021, 10:56 PM

Sure. But I’d use a smart charger, or a regular one on float setting, otherwise you could boil the batteries.

Cat320 · 04-12-2021, 09:19 AM

If you only plug in the charger to a 20 amp breaker, it should not trip. Have they changed the breaker, they wear out?

wolfe10 · 04-12-2021, 09:22 AM

Yes, you can use a standard charger or BETTER, a smart one.

If "dumb" one, plug it into a HD timer and only run it for an hour or so a day. That will not overcharge the batteries.

vsheetz · 04-12-2021, 09:42 AM

You have a 12v battery bank. Just view each pair of 6v batteries as a 12v battery. With multiple 12v battery pairs wired in parallel.

Yes. Many RVs don't play well with a GFCI.

An intelligent charger such as from NOCO would be preferable.

YC1 · 04-12-2021, 10:48 AM

Make sure it can put out ample current to support the inverter for the refer.

I'm thinking one capable of about ten amps.

You might try turning off all breakers in the rv and plugging. Once plugged in if the gfci does not trip try turning on the main breaker/s and then just the converter/inverter.

If you have a control on your built in charger set it to a very low charge rate. 10-20% will be plenty when just keeping up.

HobieBaxter · 04-13-2021, 10:00 AM

It’s a new outlet. I tested it with a GFI tester and it tested fine. I’ve heard GFI outlets and motorhomes often don’t play well together. I found if I turn off all breakers except the inverter the outlet doesn’t trip.

HobieBaxter · 04-13-2021, 10:10 AM

Thanks! Turning off all breakers except the inverter and fridge did keep the GFI from tripping. I still get a Wiring Status Error from the onboard EMS monitor, but not sure is related to the GFI. The GFI outlet tests correctly using a handheld circuit tester. I plan on contacting the EMS manufacturer (Precision Circuits) for guidance.

153stars · 04-13-2021, 05:51 PM

Can you also just plug in the fridge ? You can get a decent 20 amp marine dual bank charger maintainer for around $150-200 and maintain both sets. It can handle a beating of being mounted in RV and moisture of open floor bay.

arcaguy · 04-13-2021, 06:00 PM

If you plan on getting a charger get a regulated (smart) charger by all means. I once cooked a brand new battery over the winter with a 2 amp trickle charger. I don't know what your refrigerator draws but it will likely be more than a battery maintainer (also incorrectly called a trickle charger these days) can manage. Good luck.

YC1 · 04-13-2021, 06:15 PM

If you have a control on your built in charger set it to a very low charge rate. 10-20% will be plenty when just keeping up.[/QUOTE]

153stars · 04-13-2021, 08:47 PM

His coach plugged in trips GFCI. It could be wrongly neutral and ground bonded in CB panel many have found that.
My Tripplite inverter seems to trip a gfci only when set to charge only and then occasionally and then wont reset at all unless on invert. Happens right about the time I quit religiously checking on it to make sure batts are being charged.