I have a 2006 E350 passenger van that I am making into a simple conversion. There will be no refrigerator or other major draws from a house system, but lots of smaller draws (lights, 12V fan, recharging computer, camera, lantern batteries).

I think I want to do the following (or rather hire the following done since I have no 12V skills):

• add one or two house batteries, charged by the van but isolated when the van isn't running.
• add 2-3 more 12V power sockets, run from the house batteries
• maybe rewire the 12v power socket behind the driver's seat to run from the house batteries
• rewire the overhead lights to run from the house batteries. This is a passenger van with the lights and rear AC (which will never be used) running the length of the ceiling. There are two types of lights: those which turn on when the doors are opened (and there is no way of shutting this off, by the way), and the reading lights on toggle switches. I would at least like the toggle-switch lights on the house batteries, so that I can use them as the interior lights when parked. (If I can't turn of the automatic-door-open lights, I'll just pull those bulbs!)
• install/hardwire a fantastic roof fan, or barring that, have a plug dedicated to my Endless Breeze fan.

Does this sound feasible? Reasonable? Am I forgetting something significant? I won't be using solar on this van, as I tend to wander every day and recharge that way...and if I don't, my draw should be small enough to last a couple of days anyway.

If this is reasonable, does it sound expensive? I assume an auto electric shop with an E-350 wiring diagram should be able to quickly rewire/reroute the overhead lights, assuming that the headliner isn't a major obstacle. Surely they can install the new batteries and isolator, and add 12V sockets...or should I look for an RV place to do that?

(or does anyone in central Texas want to moonlight and help me with this task?)

Thanks for your advice --

GreyDawg in Austin

Hi I have just ordered my split charge diode for 1 starter battery, and two house batteries!
i will be planning lights, more like in a house and manly the fridge as main consumers... bad weather over here is slowing my project and photos....

I am thinking (in the Chevy) wiring the non-door ceiling lights to the house as the door ones are linked to a override switch that allows them to go off after a small delay even when ingition is on to avoid stater drain...

It sounds very feasible!!!

You're not trying hard enough...


Seriously, there can't be that many wires running back and they should be identifible by pulling the lights (whatever color+stripe is at the light, find in the front).

As far as diodes vs. isolator, I'm a big proponent of separators...you could probably use the 100amp SurePower 1610 which is around $70. Even without Shore Power it gives you the jump-start option.

You're right, I suppose -- I'm just chicken! I've never done any 12V or automotive electrical work -- my experience is limited to changing outlets and light switches in my house.

What I meant by not being able to turn the lights off is that in my Explorer, you can twist the headlight knob to dim, or shut off, the interior lights. Not so in the van. Cutting a wire may be the only choice. However, in that case, pulling the bulbs seems a bit more benign.

Diodes vs isolators vs separators? Uh, oh. Can you point me to a website where I can read about these? When I talk to an electrical guy about the work, I better ask for the right thing!

Fingers crossed, I hope that SMB will be able to refer me to a local electrical guy that they trust to do jobs right! I'll call them next week.

If you want to recharge your computer with a regular power brick, you'll need an inverter to change your van's 12V power to 110V. Inverters range widely in capacity and performance - I'm sure others on the list can recommend one. Personally, I don't have one, and instead bought a power adapter so that I could charge my laptop directly from 12V - computers are charged at something around 12V anyway, so converting to 110V just for my power brick to convert back down again was inefficient.

(Although, in the end, I have far more electricity in reserve with a single 110Ah battery than I ever imagined, so I'm considering adding an inverter anyway, for things like digital camera battery chargers.)

Re: separators, most agree that the Sure Power 1314 or 1315 are good, simple components. They sit in the middle of the cable between your starting battery and your house battery. The 1314 lets you charge one way, and is all you'll need if you won't have a charging system (solar or a plug-in battery charger) on the house side. http://www.ase-supply.com/product_p/sp-1314.htm

You could spend countless days reading about separators vs isolators, and all the different brands and options; or you could go with what most people here are using, and save yourself the trouble!

I just built and wired up my homebrew earlier this summer, so let me know if you have more questions.

Cheers!
Mike.

Go to the Sure Power web site, they have information on both separators and isolators. They also have articles explaining how each operate.

www.surepower.com

Look under "applications" and "products" (lower left of the home page)

Good Luck

Hi --

Thanks for the replies. It looks like a separator is the way to go; since I'll be hiring this work out, I may be back to y'all with a few more questions on the right way to describe/spec what I need.

Mike, I've studied the pictures of your '08 homebrew -- very nice. I haven't decided how much of the interior trim to remove from my van: there's really no need to remove the rear AC since I won't be replacing the top. Most of the lower wall trim will be hidden by cabinets anyway. The only advantage I can see to pulling it off is to improve the insulation.

What weight plywood did you use for the floor? I'm still pondering flooring options: putting down plywood and then a linoleoum/marmoleum layer is one approach, or plywood and carpet...or just carpet over the existing carpet. I'd love to put down a laminate "wood floor", but that would raise the floor lip considerably at the door sills.

For your 12V system (yep, all of my toys have 12V chargers -- I don't mess with bricks and inverters) where did you mount your house battery? (In my 1995 E150 there was an auxiliary battery tray under the hood which was very nice!)

Again, thanks for the help and tips --I'm sure I'll have many more questions as I study more photos in the gallery.

regards,

GreyDawg

I'll have to check the plywood thickness - I'm fairly certain that I used 1/4" plywood for the floor, but it may have been 1/2". With the marmoleum on top, and insulation below, it's about level with the factory door step trim.

I pulled off the interior wall trim for a few reasons:

- it gave me an extra ~12" of interior space (about 6 inches on either side)
- it exposed the van's interior sheet metal, for attaching cabinets
- my own wall panels are flat, making it easier to shape the cabinet rears to match
- and, like you mentioned, it allowed me to insulate the walls

The rear AC was a big deal to remove, and I certainly support leaving it there :) I took mine out because I wanted a bed across the back, and the AC unit took up a lot of space in the corner (shortening the bed by maybe 10" or so). But it meant custom plumbing to close the refrigerant loop (done by a local shop, not me) and cost about $300.

House battery is mounted underneath the driver's side captain's chair (I designed the brackets to accomodate it). It's an AGM, so I didn't need to bother with venting.

Feel free to ask any questions - happy to help if I'm able.

Cheers!
Mike.

PS - you can certainly install the separator yourself, if you want to give it a try. There are 3 wires:

- a heavy-gauge cable from the main battery to the separator
- a similar cable from the separator to the house battery
- a lighter gauge (say 14AWG) from the separator to some bare metal on the chassis

All of the connection points have posts, so you're just crimping on some lugs and screwing the wires down. Save yourself some bucks, and gain a little confidence with your electricals.

Hi Mike --

I guess I'm a chicken: I'll take on anything except the electrical. If I had someone supervising, I'd do it in a flash, but with no one looking over my shoulder...

I talked with an electrical shop today about doing my electrical work, and took them a diagram based on Jage's "code" on another thread. It made sense to them, the price is quite reasonable, and so that will be my splurge. I must decide beween a 110 AH vs 220 AH battery -- AGM, of course.

Now, the floor. I"m thinking I can do the floor before making a decision about whether to pull off the wall trim; if I put down the floor and later pull the wall trim, the gap will be covered by cabinets (I hope). I will pull the factory carpet up this weekend exposing the bare metal floor. Quarter inch plywood sounds good, but what insulation did you use beneath it? Anchored with....screws? Or adhesive? I too would like to make this van as green as possible. Then linoleum or marmoleum on top, unless I can find a reasonable bamboo flooring material.

Thanks,
GreyDawg

Get them to add a basic switch to your dome lights to shut them off. On top of everything else it should be an inexpensive task for them.

I took a look last night: the plywood is 3/8". I used the foil-backed cotton on the floor; plywood held down with screws.

Cheers!
Mike.

Good point -- thanks! There are two types of light in the celilng -- those triggered by the doors and the reading lights triggered by switches. I asked that the reading lights be put on the house battery, but yes, if they could insert a switch so I could turn off the door-triggered lights, that would be much more elegant than my plan to pull the bulbs!

I've already made notes of a couple of other things to discuss/spec, following our conversation of yesterday. The key decision will be where to place the AGM, since that will dictate whether I do the floor first (if it is inside) or second (if it is bolted under the frame, like the SMB batteries in the step of the RB-50. Does mounting there require cutting a large hole in the floor? I can't recall...

Thanks! I assume you used sheet-metal screws through the plywood and insulation, and did not separately secure the insulation, right? Did you just lay the insulation down, or did you try to fill the ridges in the floor by cutting and laying additional strips there (ie put strips in the troughs, and then a solid piece of insulation as a blanket over those?).

Off to hunt down marmoleum or linoleum after work today -- fun!

GreyDawg

You don't have to cut a hole in the floor. The hole in the floor allows you to access the battery from the top, whereas the starter batteries and 4D that is outside in my rig have to be dropped to access or change them.

The 4D is so heavy that I don't think it will be movable without shop tools no matter where you put it, and I don't think top access is worth a hole in the floor. You're not supposed to do maintenance beyond replacing as far as I know, and I'm managed to reach and remove both the top and cables from the 4D under the van.

That's for an emergency. To replace or pull for testing the whole frame can be unbolted- I guess that's an important thing, make sure however the battery is placed it's removable: don't let them just weld it in place.

I'm curious, does anyone have a through-the-floor access to their batteries that isn't an artifact of having to cut the side door step to create enough room for the 4D? Like one in the center somewhere, where the battery has to be dropped and lifted through the floor?

I'm going to have follow-up conversation on Monday with the folks who will do the 12V work, so I'll push harder on exactly how/where they think they should mount the battery, and what that means for cutting the van (which I wish to avoid). I may also go over to SMB on Sunday and crawl under a van or two, and look.

Next question: I have to choose a battery. AGM of course, but my two choices are 105AH or 220AH (which I believe y'all call the 4D), the latter at 2x the cost of the former. My gut is to go with the 220AH, but the installer thinks I'd be throwing away money since I will only have a 12V system (no inverter, no 110 sockets, no shore line, no appliances ... yet).

However, quick back-of-envelope calculations show that one day not driving, sitting in a hot place and running the Fantastic Fan 12 hrs (1.86Amps on low, 2.2 on medium, so guestimate 2 amps), would eat 24AH; two days of sitting put in a beautiful, but hot, place would consume all my "available" AH in the smaller battery without running any lights, or 12 volt toys (free-standing radio, 12V plug for computer, cell phone charger, camera battery charger, rechargeable lantern).

And I might eventually tire of my marine ice chest and add a used refrigerator...

Without a solar system (yet) it seems like the smaller battery would be foolishly frugal, and that I'm better off dropping the extra $200+ for the larger. And that's just considering current 12V consumption, not future additions.

Or have I totally biffed my calculations?

(Oh, yeah: they're also worried about the weight of the bigger battery and balancing weight in the van, which is a valid concern. Since the larger battery and I weigh about the same, I'll argue that they can put it anywhere in the front half of the van on the passenger side and be balanced since I sit in the driver's seat. Is that logical? Or nuts? )

Thanks!