Have an RV. Apparently in the past, it has been examined for electrical system problems that have never been fully resolved. Having tried to troubleshoot such problems in the past, I really have no desire to have another go at it and don’t think the repair shop is going somehow get it right THIS time.
The main problem appears to be this. When you get to a campsite and get all set up, you plug into the outlet there to run the electrical stuff in the RV. It works fine, except for one problem. The charging system for the “house batteries” never seems to detect that the batteries are fully charged and will keep charging them at a high level until they are fully cooked and ruined. In the past this has been dealt with by disconnecting the house battery cables. Its a pain to do and some folks have forgotten to do it (or more likely couldnt be bothered), ruining some expensive batteries on more than one occasion.
Plan A is to put a heavy duty switch on the power cable leading to the batteries. That will at least make it much easier to do. Get there, lift a panel, and disconnect em by throwing a switch. I don’t see any real downside to that plan.
But, this brings up a question. It is hard to tell if the charger is doing the same thing when you are driving down the road and the RV generator is running (and it is powering the AC system and the fridge). Would having the batteries disconnected while the generator is running be bad for the generator? Obviously the batteries are going to have to be “on” some parts of the time be used when needed and to get the occasional charge.
And, then there is this problem. Currently the house battery system consists of two 12 volt batteries wired in parallel. Its been my understanding that without a fancy electrical system, batteries in parallel is just a bad idea. I suspect at some point in the past somebody could not find two 6 volt deep cycle batteries to put in there in series, so they threw two twelves in there in parallel.
I agree that it’s time to replace your charging system. A well designed one will not do what you’re saying.
On the issue of having two 12v batteries in parallel you’re not really harming anything, and it does give you extra amperage if you need it, but unless you are away from “shore power” for an extended period of time and run heavy loads (like your refrigerator) without recharging, a single battery should be sufficient.
The drawback of two batteries in parallel is that they will tend to “equalize” each other. If you have one fully charged battery and one weak battery in parallel, the weak battery will drain the other one to charge itself, rather than using that power for your RV.
The old converters made by Magnatek and also sold under the B & W label used a small charger that charged whether the battery needed it or not. I replaced the one in my camper with one these, which I leave plugged in 24/7 and which will charge the batteries much more quickly:
Got to do a bit of rewiring to install it, and it doesn’t include its own 12v fuse box, but they are readily available at NAPA.
I gutted the old Magnatek converter, and installed the PD unit into the Magnatek case, preserving the old fuse panel and 120V breakers in the Magnatek. This made for a no mess installation in the RV. In the same volume I went from a ~10A charge rate to 45A, so I can charge the house battery in a couple of hours instead of overnight.
A bit of googling will find photos of how to do this.
Hey guys. Thanks for the input and info. I managed after a good bit of digging to find some actual info on the RV electrical system. It sounds like you had two options when it came to the charging system. On just stayed on high charge the whole time (wtf wants that?). The other option went from high charge rate to low charge rate after being plugged in for 13 hours.
So, my current WAG is that they put in the cheaper and bad option or the good option is in there and not working right. Did find the charging unit, doesnt look as bad to replace as I first imagined.
Just wanted to say thanks again. I got the progressive dynamics unit. They had a model that drew and put out the same wattage that the old magnatek unit did, so all I had to do was pull the unit and disconnect/reconnect a few wires. They had the old unit pretty well hidden but I eventually found it.
The new unit also appears to be much better than the old one. And it DID turn out the old unit was the one that had the “option”(aka the cheaper POS one) where it just stayed on high charge and would charge your batteries to death if you left the RV plugged in for more than few days. And this was something that was buried in the fine print in one stray pamplet among hundreds of pages of documentation and required somebody that has a basic understanding of electronics and an ability to read between the lines to “catch”. The cheapskate engineer that thought this was a good idea should be kicked in the nuts.
I had a motor home with 2 12volt batteries. It had installed in it a battery switch. I could run the RV on either one of the batteries or both. And I could turn the batteries off if I wanted to.
The motor home did not have a genset. The way I used the switch was: If I was using the motor home at a camp ground with out electrical hook up I would switch to one battery. When I was ready to leave or if the first battery became flat I would switch to the second battery start the engine. After the engine had wormed up I would the switch to two batteries and charge both.