Community Forums

16bounder · 12-03-2021, 12:53 PM

My motorhome as 4 batteries arranged in series, and it seems my inverter may be on the fritz, as it is showing fault ac overload. So, in my thinking (not too sure of) since they are not being charged via inverter, I will revert to using a "regular" battery charger. The batteries are 6volt-can I just plug positive and negative to the ends of bank of batteries? Negative on one end and positive on other end....basically charging ALL as one???

wolfe10 · 12-03-2021, 01:03 PM

Hopefully, your 4 6VDC batteries are in series/PARALLEL. This is assuming your system is 12 VDC.

So, two pairs of two batteries in series= 12 VDC

Then each pair in parallel= larger bank @ 12 VDC

DavidEM · 12-03-2021, 01:47 PM

What is this regular battery charge? If it is an automotive type then they are usually not a three step "smart" charger and will ruin your batteries if left connected for too long. But they are fine for charging up as long as you disconnect them once the batteries are full.

David

16bounder · 12-03-2021, 02:56 PM

Yes, automotive type - and yes, was thinking of doing that, disconnect every so once in a while......Thanks for the reminder. Gotta limp along till supply chain catches up!!!

DavidEM · 12-03-2021, 04:09 PM

Ok but don’t leave it connected more than a few hours once the batteries are fully charged. What is the amp rating of this charger?

David

amosnandy · 12-03-2021, 05:27 PM

Quote:

Originally Posted by 16bounder

My motorhome as 4 batteries arranged in series, and it seems my inverter may be on the fritz, as it is showing fault ac overload. So, in my thinking (not too sure of) since they are not being charged via inverter, I will revert to using a "regular" battery charger. The batteries are 6volt-can I just plug positive and negative to the ends of bank of batteries? Negative on one end and positive on other end....basically charging ALL as one???

Your inverter never did charge the batteries. It turns 12v into 120.

You converter charged your batteries and you possibly had a inverter/charger.

What makes you think it is not charging? Battery voltage dropped? When the engine is running do they charge? Since it is showing an AC overload fault it may just need to be reset. If you drew to much power it shut itself down and usually in an inverter/charger that shuts everything down. Even on mine last year that had an overload fault, when reset, it would not invert, but it did still charge.

But as others said, an automotive battery charger will charge them up. Just take it off when they are fully charged.

16bounder · 12-03-2021, 05:47 PM

We are hooked up to shore power for several months. The history is that somehow the Bussman fuse blew, replaced that and the new one blew as well. I called Magnum and after being talked thru several scenarios, it was determined that I probably have a bad inverter. Thinking of possibly getting a certified RV repair guy schooled in electric/inverter to come take a look see.

16bounder · 12-03-2021, 05:48 PM

Also have 4 brand new batteries, as was told that since first fault on monitor showed dead battery.....

andy29847 · 12-03-2021, 06:05 PM

If your motorhome is like mine, all 12v power comes from the batteries. If you used the motorhome for a spell with the inverter/charger not charging, you have run the batteries down. If the batteries are top low when you get the inverter/charger started, the charger will cut off. I would charge the house batteries with you car charger until they reach 13+ volts. Then I would reset the inverter/charger and see if it will go back to work. You should probably check the water levels in your batteries too.

Persistent · 12-04-2021, 08:33 AM

Quote:

Originally Posted by 16bounder

My motorhome as 4 batteries arranged in series, and it seems my inverter may be on the fritz, as it is showing fault ac overload. So, in my thinking (not too sure of) since they are not being charged via inverter, I will revert to using a "regular" battery charger. The batteries are 6volt-can I just plug positive and negative to the ends of bank of batteries? Negative on one end and positive on other end....basically charging ALL as one???

As noted in previous post, 6 volt batteries are wired in series/parallel. So, 4 six volt batteries will be two pairs, each pair in series to make 12 volts. The two 12 volt pairs are then wired in parallel to increase capacity.

Connect the external charger to the 12 volt output of each pair. Do not connect to an individual 6 volt battery.

Portable automotive 12 volt chargers come in many different flavors. Some are as smart as your built in charger. Some are not. Older designs could damage storage capacity and boil batteries dry in a day.

Newer designs are closely regulated and will not harm your batteries. How can you tell?

Advertising on the charger may tell or may just confuse.

Get a digital voltmeter from your local hardware store. It may cost $20.
Measure voltage from battery terminals to ground (RV frame or other metal structure).

Connect the positive charger cable to the 12 volt positive battery terminal.
Connect the negative charger cable to the frame or metal structure. If area around batteries is well ventilated, you can connect to the 12 volt negative battery terminal. (Sparks can cause a fire. Charging batteries emit hydrogen gas.)
Turn portable automotive charger "on".

Monitor battery terminal voltage with your new digital voltmeter. Voltages should slowly rise to the preprogrammed voltage of the charger. The voltage may be 13.2, 13.6, 14.4 volts.

It takes 14 to 18 hours to fully charge lead acid batteries. 24 hours may be useful for batteries that have been abused. Charger may be left in place for long periods as long as terminal voltage is 13.8 volts or less.

14.4 volts is OK for a few hours. Many chargers bring voltage up to 14.4 volts for a few hours then drop back to 13.6. 13.6 is good for long term occupied use.

Higher than that will be a problem after a while. 15 volts or more, for more than an hour is bad but it may be enough to restart your built in battery charger. Some built in chargers refuse to charge when terminal voltage is below say 11 volts.

I wish you good luck and happy trails ahead!

16bounder · 12-10-2021, 12:20 PM

Thank you all for the suggestions and thoughts on my delimma, the inevitable has come to be. The converter part of the inverter's mother board seems to be toast. Hopefully it can be repaired-depending on part availability...

Winemaker2 · 12-10-2021, 02:10 PM

Quote:

Originally Posted by 16bounder

Thank you all for the suggestions and thoughts on my delimma, the inevitable has come to be. The converter part of the inverter's mother board seems to be toast. Hopefully it can be repaired-depending on part availability...

Thats one of the reasons I prefer using a relatively inexpensive batty maintainer for storage instead of running inverter/charger 24/7 just to maintain battys.
IMO electronics have a finite life and prefer to use a maintainer for storage.