Battery box for a camper van

Re: Battery box for a camper van

That's similar to what I'm planning for my camper van. Mine has two battery trays under the hood. One for engine battery, and one for house battery. I don't have any other place to put the batteries outside the cabin, but I have a perfect place under the couch, so I'll be putting two batteries there.

Since they'll be inside the cabin, I don't want regular FLA (flooded lead acid), with the venting issues, so I'll be using AGMs which are sealed (unless you overcharge them to the point of blowing the seals).

I'll most likely be going with the Morningstar SunSaver duo charge controller, since it can charge the house battery and also keep the engine battery topped off. It's a PWM charge controller, not MPPT, so it costs quite a bit less than an MPPT controller. PWM is fine though for a single panel setup, since MPPT isn't going to increase my harvest enough to really even notice (probably a single 135w PV flat mounted on the roof), and certainly not enough to justify the extra cost.


EDIT: Oh, and the way I'm planning to wire it is to run from the batteries (under couch behind driver's seat - I'll make a wooden box to hold them) to the left rear corner where there is already the shore power breaker box (holds two breakers, but only has one 15a in it) and the battery charger. I'll put a "power distribution block" in a metal box:

http://store.solar-electric.com/16220-1.html

I'll connect the batteries to the large terminals on the block (big fuse (+) and battery monitor shunt (-) at battery end (also a disconnect switch (+) on the front of the battery box (reachable under driver's seat))), and to the smaller terminals I'll connect the solar charge controller output, the inverter's 12v input, the shore power battery charger output (right now a 10a Shumacher, which I plan to swap out for a bigger Iota), and a 12v fuse block for the 12v loads.

(Actually, I plan to drill holes for 4 resettable 12v breakers and mount them in the box where the power block is, and then run wires from the block to the breakers, then connect the smaller devices to the breakers.)

The charge controller will also mount back there as that will keep all the electric together in the back, and I'll put an extra smoke detector just above the collection of electric widgets.

There is a split-charge relay off the alternator, and I'll probably change out the house battery under the hood for another starting battery and then add a switch so that I can activate the split-charge relay so if need be I can jump start off the 2nd under-hood battery. I'll then run the 2nd battery output from the SunSaver Duo to that battery just to keep it topped off. The battery temp sensor will go to the in-cabin AGMs.

Down the left side is the driver's seat and the couch behind that, and behind the couch is the cabinet with the fridge. On the rear of that cabinet is where the shore power breaker box is now, so getting down into the van from the PV is nothing, I'll just drop down through the existing fridge vent and then poke through the side of the cabinet to the charge controller.

To access the electrical stuff, I just open the left rear door and there it is.

I'll wire the existing shore power breaker box, to the output of a 30a 120v DPDT relay as a poor man's transfer switch (in its own metal box). Incoming on the relay will be the feed from the shore power plug, and the feed from the inverter. When not energized, the relay will default to feeding the breaker box from the inverter, but the coil will be wired to the shore power side, so if there is shore power it will energize and connect the breaker box to the shore power instead.

I have a portable generator, and I just plug the shore power connection into it when I use it.


Another EDIT: Oh, and the Iota charger will be wired so it will only work when there is shore power. I'll add another breaker to the existing 2 breaker box (luckily it's a 220 box so I don't have to change it out), and wire it so that that breaker will get power from the shore side of the transfer switch, and then hook up a plug to that breaker for the Iota.