Bought an old Class C - Electrical question?

Most experts do not recommend running batteries of different ages together - it can reduce the operating time of the newer batteries significantly.

Your RV isn't going to use a lot of battery power unless you added an inverter and are running 120v appliances off them. Did you buy deep cycle batteries or regular starting batteries? If starting batteries, they will not last nearly as long as promised due to the repetitive drain and charge (hopefully you did get deep cycle).

I would recommend staying with the 2 battery bank and putting $2-5 away each month for replacement batteries. If you have a problem later, you'll have the cash to buy the new batteries; if you don't have a problem, then you'll have extra money to celebrate the new house.

If you really think the old batteries have value, then sell them on craigslist and put the money towards your "battery nest".

Thanks, Bobo-
It's a bit of an interesting situation. The RV is parked on some property in the redwoods my friend recently bought. She's going to build a house in the next year or so, but for now there is no electricity or water - so we are basically boondocking. The genny in the old RV doesn't work, so we bought a portable one.

With the batteries - I put two brand spankin' new ones in - I'm just wondering about reconditioning the other two and adding them in parallel for a total of four. I just hate to waste them. But, we will always have the two new ones to fall back on if the reconditioned ones******out.

I am not a battery expert, but if I were going to use the batteries for boondocking, I would not want reconditioned. Nothing would ruin a trip like battery troubles.

And if you are not boondocking, 1 battery is enough, since you are plugged in.

Hey all!

Quick update! Thanks a million for all of your help and advice! New converter, batteries and fuse box are making all the difference. I honestly wouldn't have known where to start without all of your help - and now the entire system makes perfect sense.

One last (on this topic) question: What are all of your thoughts on using reconditioned batteries? The two "old" batteries we replaced are actually not that old, but have been overcharged and abused to high-heaven. With the electrical compartment redone and organized, there would be plenty of room for 4 batteries and I'd love to recondition them and add them to the bank. A 4 battery bank would let us last forever considering I've also replaced everything with LED and low-power equipment. I really hate to just turn them in since I think they can be salvaged.

Thanks again everyone. This has all been super helpful! To Bordercollie's point, it would be great if I could find an original manual - trust me, I've tried! Every site I could possibly scour to no avail. That said, This RV is 37 years old, and stuff has been seriously cobbled together since then.

However, based on all of the awesome information and suggestions you all have provided, I think I have a plan! Basically, using the current inputs and outputs that are already there, I'm going to start from scratch with a new converter and add a distribution panel. The current 110v setup is basically separate: 110v shore comes into a breaker box with 2 breakers, then out to a switched outlet and out to the 110v stuff onboard. There is no inverter, so 110v only works while plugged into shore power, which is ok for now (I might add a tiny inverter just to power a DSL modem and router from batteries).

Anyhow, below is the sketch I came up with. I'd love any and all thoughts if you think I've missed something! Thanks again for all of your help. I really appreciate it.

Link to Diagram

It would help if you could source a 12vdc and 120vac wiring diagram for the housebox from Midas or whoever may have bought them out. There are some services that provide reprints of old RV manuals, etc. Google!

Avoid Magnatek, Parallax, WFCO

There are all sorts of variations possible. Not infrequently the converter, DC load panel, and AC load panel are all in one unit. Sometimes DC and AC distribution are combined, with a separate converter. Probably sometimes a converter and DC are combined, with a separate AC panel.

Having some sort of a DC distribution panel is a good idea. Certainly all the DC circuits need to be properly fused somehow or another for safety, and having inline fuses helter-skelter is hard to keep track of and untidy and generally not best practice.

I suspect my motorhome is roughly typical of the usual DC wiring, though there are very many variations. From what I've made out, the house battery positive is connected to a large fuse (I'm guessing maybe 100A or so, I don't know exactly) to protect against a catastrophic short circuit somewhere.

After this large fuse, there are a few things connected by a short bus bar. There's the isolator relay that connects the house battery and the chassis battery together when the engine is running so that the alternator charges the house battery (and also when the emergency start switch is pressed). There's a self-resetting circuit breaker, protecting a wire that goes to the converter output. There's another self-resetting circuit breaker for the wire that goes to the main DC distribution panel (with a "salesman switch" or master shutoff in between). Finally, there's another self-resetting circuit breaker, I assume for circuits that are always powered, at a minimum including the control for the master shutoff switch. (There is, of course, no reason other than convenience why these various self-resetting circuit breakers couldn't be fuses or manual circuit breakers.)

From the DC distribution panel, individual fused circuits go off to all the 12V things throughout the motorhome, as expected. Mine uses the usual blade-type automotive fuses, as do most of the new ones you're likely to find. Marine, RV, or automotive fuse panels would all be more or less suitable; the RV ones mainly offer neat-looking covers and mounting and so forth, but are not unique in terms of functionality.

Not "required" but why not improve this rig while you're at it...

The IOTA unit that came with our Jayco is all in one;

Converter
Charger
12VDC Distribution with Fuse protection
120VAC Distribution with Circuit breaker protection

This is only personal to me, but I like separate components. For our boat, for example, it's possible to get a combination depth sounder AND navigational GPS. I prefer two units. Nice to save space, but if one fails I don't have to replace the other.

I have the room in our coach, so to replace the IOTA, I'd be looking for a good Converter/Charger. Those two seem to always be together. But I'd like it either completely separate from Fuse/Breaker Load Center. That or included in a common rack with Converter/Charger and Load Center in a way that I could replace either.

Looking to the Circuit Breaker/Load Center for 120VAC I'd check big box stores for small residential panels or "sub panels." What I'd be after is the least expensive SINGLE breakers, like GE or SquareD HomeLine. I don't like the Duplex 120VAC breakers the RV load centers use. They are more expensive, one overheats the other, and you have to match the sides. For example, branch circuits are 15/15. But Main and A/C occupy a 30/20. Get a 20/30 and you have to re-wire, re-label, or re-member.

The two 120VAC breaker boxes I mentioned were GE residential. Home Depot every time, and you can get reasonably priced GFCI breakers to protect your circuits in wet areas like kitchen, bath and outdoor.

For the 12VDC panel I'd at least check marine. The one we had in that coach wasn't marine. It was a steel box with cover and used glass fuses. Never needed to know where it came from.

Thanks Drew!

Here's another question (probably a totally rookie one at that). Do these converters requite a separate distribution center, or am I able to wire the 12v lights, etc right to it?

In the current setup, there doesn't appear to be a distribution center, although there are loads of wires bundled together under the original converter - and I'm pretty sure these are the wires for all of the 12v gear. It was too much of a huge pain to totally take it apart this trip (the RV is parked about 3 hours from home and very remote) since we still needed power. So I'm thinking that the original has a built in distribution center, or everything is just harwired to the battery bank.