Wiring/Charging Question

[MakersTeleMark]

I'm looking to minimize the work on the LH Alt that charges the front battery and tap into the negative side of the rear battery to get 12v.

The goal is to have the rear battery isolated and protected while allowing it to charge a 3rd deep cycle battery in the camper while the truck is running.

My theory is that if I connected the negative side of the rear battery (or perhaps directly off of the 12v bus on the firewall) I could connect it to this:

DC battery isolator and split charge relay for RV, car, and truck applications

and then I'd have solved my problem.

Any thoughts about this? I know I could go directly off of the front battery, but figured it, and it's alternator are already sufficiently taxed and might as well use the rear one.

 

[drgreg]

What type of loads are you trying to supply?

 

[MakersTeleMark]

Just for charging a simple yellow optima.

 

[doghead]

In order to use the rear battery/alternator, your camper circuits would need to be isolated from the trailer ground(might be already?)

I think you idea is a little over complicating the situation. I'd simply charge the camper battery off the front battery, via your trailer plug.(you are going to use a round connector, right?)

 

[MakersTeleMark]

It's not a trailer (slide in popup) so there is no existing wiring. I'll go ahead and wire it with some heavy gauge battery cable off of the front battery and isolate it.

 

[zout]

Products | Battery Equalizers

Look into battery equalizers that will charge 24v and 12v at the same time as long as your main powered unit it running. it will charge them individually as well. You can purchase different amperage units.

So if you are looking into a deep cycle for the popup in the rear - and keep it charged while your running - here ya go.

 

[MakersTeleMark]

Products | Battery Equalizers

Look into battery equalizers that will charge 24v and 12v at the same time as long as your main powered unit it running. it will charge them individually as well. You can purchase different amperage units.

So if you are looking into a deep cycle for the popup in the rear - and keep it charged while your running - here ya go.

Does that act as an isolator as well? Meaning, it will not charge the 3rd battery unless the engine is running, and also protects the 3rd battery from participating in starting duties?

 

[zout]

correct.
If your 24v needs charged and your deep cycles do not require a charge - it monitors that.

If you start your truck - it only draws from the 24v batteries keeping the deep cycles blocked.

I have a 100 amp Vanner in our's with 4 deep cycles - and it works perfect for charging and keeping them up going down the road.
I also have a 3000 watt inverter charger and Onan genertor plus 50 amp for shore power - I can manage the deep cycles from 4 different sources - BUT the 24 volt only get charged from the generator.

I do have a big thread on the stuff if you have nothing else to do - check it out

 

[MakersTeleMark]

In order to use the rear battery/alternator, your camper circuits would need to be isolated from the trailer ground(might be already?)

I think you idea is a little over complicating the situation. I'd simply charge the camper battery off the front battery, via your trailer plug.(you are going to use a round connector, right?)

Back on this post Doghead, there is currently no physical ground in the camper besides the - post of the camper battery.

What if I used 12v power from the rear - battery routed through a relay to the + of the camper battery, then ran a ground cable from the camper battery - to a - bus in the cab connected to the chassis and front battery -?

 

[xenocath]

i been looking at doing something similar only with a towed cargo trailer instead of a truck bed camper. in my seeking for answers i hit on this web site explains alot hope this helps Cheaprvliving.com