Forum Discussion

Mako_Kupo's avatar
Mako_Kupo
Explorer
Jan 05, 2018

house battery install, basic

hey guys, I'm back! I've dug through forums and other resources, but cannot find a direct comparison to what id like done. I restored a '79 ford class C (E350 chassis). it was really poorly rigged and quite dangerous when I bought it, I had a mechanic go through it and bring me back up to code and safety standards. this included disconnecting the house battery from the alternator for some reason.. I'm no mechanic. the reason was everything was being run off the starter+house battery in parallel, there was zero options to turn one off, the other, or both. it was both batteries, all the time.

now, its ready to have power again. I purchased an 85ah flooded deep cycle a Duralast 27 series, its dual purpose but for me will work great. I only need 150w output at any given time. what id like to do is charge both batteries while driving/engine running, and be able to turn off the starter battery manually, or automatically though I've heard the automatic ACRs will kill your battery in about a month if left sitting. I've heard conflicting information about this, and. really need it cleared up. I only need 150w because it will be charging my goal zero yeti generator at 150w, and everything else runs form the yeti(for now).

is this a good option? is it as simple as it seems? connect starter battery to one side, house to other, and be done with it? if thats the case, its perfect. https://www.bluesea.com/products/7610/SI-ACR_Automatic_Charging_Relay_-_12_24V_DC_120A

or should I do a manual switch, and if so, basic disconnect between battery A and B? or a 4 position?
  • What enblethen posted is probably about the simplest to understand and quite commonly used. I would put a fuse or circuit breaker between the auxiliary (house) battery and the wire to the solenoid, like the one at the engine battery end, to protect the wire run, and maybe upgrade the size of the wire and the breakers/fuses correspondingly (and the rating of the solenoid, if needed), but the general idea is the same. This is what I have on my class C, in fact, and it works out just fine in practice.

    Often there is a pushbutton switch in the control line to the solenoid for an emergency start circuit. The common contact goes to the solenoid, and the normally closed to the vehicle accessory power source as indicated. The normally open contact is wired to a circuit on the house 12V system. Pushing the button then closes the solenoid switch (and so connects the batteries together) in case the chassis battery is drained, basically a built-in jumper cable set.

    Your "generator" is nothing more than a battery pack and inverter. You would probably be better off for many things (certainly 12V things) connecting them to the house battery rather than having another intermediate battery. I'm assuming you do have some 12V lights and appliances.
  • This was/is a common method of isolating the chassis from house batteries and is used for charging house batteries while rig is running.

    Charge relay

About Technical Issues

Having RV issues? Connect with others who have been in your shoes.24,194 PostsLatest Activity: Feb 01, 2025