Need some educated advice on camper electrical problem

[xtremexj]

I have been chasing a problem with my camper electrical problem the last few times I've been out. Just out of the blue I started having issues with the batteries not wanting to power up the camper. Everything works fine on shore power but as soon as I connect the house batteries I get nothing. I run dual 6V deep cycles and they show over 13V when they are charging on the solar panel but once connected to the converter they barely show 2V. I thought it had to do with my battery wiring so I cleaned everything up to make sure I had good contacts but no luck. I was convinced it was the converter so I went and bought a new one today and changed it with no change in my problem. Could I have a bad battery even though they show good charge but drop to nothing once a load is connected? I'm at my whits end with this and we are heading out next weekend for some primitive camping and I need to get this sorted. Any help would be greatly appreciated.:ylsmoke:

 

[DiploStrat]

Dead

Sounds like you have some very dead batteries. (11v is generally considered to be very dead; 2v is off scale.)

You should be seeing a voltage of over 14v when on solar charge and a resting (i.e. not connected to a charge source) voltage of between 12.7. and, say, 13.2v.

When batteries die suddenly it is usually because the charge source (alternator, solar kit, shore power) failed.

With that guess, I will await dwh's sage comments.

 

[dwh]

What DiploStrat said.

Plus...

Bad batteries can often behave normally as far as charging. I.e., they'll charge up to full voltage and often sit at a normal resting voltage. But then as soon as you put a load on them they drop to nothing. Often, the only imediately noticable difference is that they'll reach "full charge" a whole lot quicker than they should.

If they are showing 13v on solar (technically, probably more like 13.6v?), that would mean that the solar charge controller (if you've got a good one) has dropped into float mode. So it thinks the battery is full.

You say "converter". What converter? Some - like older Magnateks - are well-known battery killers. The problem is they are designed to convert incoming 120v to 12v to power loads - but they do a terrible job of battery charging. Some won't ever get the battery fully charged, and some will hold the battery at too high a voltage indefinitely as long as they are plugged into shore power.

You say you bought a new converter. What did you buy?

Best Converter has a kit to upgrade a standard (translation: crappy) standard RV converter by replacing the transformer with a decent multi-stage charger. Note the crappy little transformer in one of the pics on this page:

https://bestconverter.3dcartstores.com/MagnetekParallax-to-Ultra-III_ep_8-1.html



So without more info, I'm gonna take a guess of: Batteries are toast. Most likely due to crappy converter.

 

[Martyn]

Start out by load testing the house batteries. This will determine if they are the problem or not. Once the load tester is connected you'll see the initial voltage (13.0 volts), you will apply the load for 10 seconds, and see where the battery voltage falls to. A weak battery will go down to around 10.0 volts. If yours drops to 2 volt you are just carrying a couple of lead weights around.

Next make sure you are getting a charge back to the house batteries from the vehicle when it's running. Then make sure the battery isolator is functioning and your vehicle is not drawing power back from the house batteries. If there is a parasitic draw from the vehicle you will need to address the issue.

My last choice would be looking at the converter. All the converter is doing in this case is taking 120 volts and converting it to 12 volts to charge the house batteries. As your camper has solar, and most probably a charge from the vehicle, the converter is just a third method of charging the house batteries while plugged into shore power. So it may not charge the batteries while plugged into shore power but the other two methods should still be functioning. I'm presuming here that the solar is working as designed, if not that's a different discussion.

 

[xtremexj]

I am referring to the camper converter. I have now confirmed that it is the batteries. I charged a Yellowtop Optima overnite and tried it this morning and everything works fine. Obviously there is a problem with one or both of my 6V batteries so I'll have to get them checked out.

I guess I will have a spare converter on hand if I need one considering that the new one was installed.

Thanks for your input everyone.