[danlash]

I saw a couple of posts from a few years ago about mounting the house batteries under the van. I was wondering if anyone has done this and what their experience has been?

My main questions:

1) Do the batteries have to be in a box? (assuming yes, but checking)
2) Are there any restrictions or recommendations for box materials?
3) How do you seal/not seal the box?
4) Do you use a grommet or something to pass the power inside?
5) Is there anything pre-built or would I have to build a rack/box?

 

[keeponvaning]

I saw a couple of posts from a few years ago about mounting the house batteries under the van. I was wondering if anyone has done this and what their experience has been?

My main questions:

1) Do the batteries have to be in a box? (assuming yes, but checking)
2) Are there any restrictions or recommendations for box materials?
3) How do you seal/not seal the box?
4) Do you use a grommet or something to pass the power inside?
5) Is there anything pre-built or would I have to build a rack/box?

1. No (many big trucks just hang them off the frame wide open)
2. Sturdy
3. Depends of the box
4. Yes without a doubt!
5. Yes (as a matter of fact while cleaning out my junk room a few days ago I found a steel drop in the floor battery box I bought 30 years ago and never used)!

 

[seapro]

A drop in the floor battery box is the best. I have seen installations where the batteries were hung underneath and needed to be lifted up from below to install. This is difficult -- almost dangerous -- to handle the heavy weights overhead.

 

[medicineman4040]

Not that it applies to me but I'd love to see images of a drop-in battery box. Very clever.

 

[phil]

Promaster's frame is perfect for drop in boxes.

This is on a sprinter post 28 https://sprinter-source.com/forum/showthread.php?t=36265&page=3

Promaster cab and chassis post 9
http://www.promasterforum.com/forum/showthread.php?t=57626

If you move the exhaust and e brake cable one could install large boxes.

 

[Signalhill60]

I mounted 4 golf cart batteries under my 159" PM. it was a fair amount of work but worth it in the end. I fabricated each battery frame out of 1" angle iron 3/4 round tube and 3/8 all thread. The angle makes up most of the frame and holds the battery securely in place and the round tubing and the all thread is the mechanism used to raise and lower the battery.

To install a battery the frame is lowered, The battery needs to be lifted about 2 or 3 inches up into the frame and then turn each corner bolt 1 " at a time in a criss-cross pattern. The all thread has been fabricated into a 13" bolt is in each corner. Each battery is hung from the floor with 4 5/16" bolts. The pictures show one frame open and the other closed. The other shows two of the four batteries in place. The cables go through the floor via a heavy duty rubber grommet with a 200 amp catastrophic fues between the batteries and master shut switch.

 

[VanDiesel]

That is a really slick and relatively easy solution to carry the batteries under the van. And, no big hole in the floor!
Thanks for posting the pics.

 

[Winston]

I'd love to see images of a drop-in battery box. Very clever.

Unfortunately we didn't take photos, but while visiting Opt Overland of Fort Collins last Sunday, we nearly stepped into a 'recess' in the floor of one 'van in progress' and were informed that this was something "the customer" did and it was for the battery. It was a completely enclosed (four sides and bottom) steel box extending below the floor that allows for the insertion (and presumably wiring, testing and monitoring) of the house battery from inside the van. Give them a call and we bet they'd be happy to 'photo document'.

 

[Hein]

We recently learned that one of the battery boxes that we designed for the Transit will very likely fit under the Promaster. We would be glad to work with a Promaster customer to verify this. This is a large box and a secure mounting system. The inside dimensions of the box are 23.42 x 12.29 x ~12" headroom. We recommend AGMs and connect all cables in advance which is actually a slick way to get batteries configured and bench tested before installation. AGMs are maintenance free so no need or reason to access them. The box can be removed and new batteries installed after the 4+ years of life they generally have.

This is a photo of the Transit box just prior to installation. We even mounted and pre-wired the main DC fuse/disconnect/distribution panel and mounted it on the outside of the box in a water proof enclosure. Final connections to chassis and house systems can be safely made once the box is in place under the van. Shunt for battery monitor and negative buss bar are to the left. Electrical components are securely mounted to a thick piece of Celtec expanded PVC which provides added electrical insulation.

 

[Swoop]

Promaster's frame is perfect for drop in boxes.

Promaster cab and chassis post 9
http://www.promasterforum.com/forum/showthread.php?t=57626

The PM chassis cab frame is ~9.5" deep. The van frame is ~4" deep.

 

[dobermin]

What do you think about this:

http://www.mirageinc.com/battery-box-recessed-for-12v-marine-batteries

 

[seapro]

As I said prior any drop in box is better than hanging from below. Any local metal working shop can make them out of aluminum or steel -- just give them the dimensions (and a few $$). Professional Class B conversion companies use them. If steel they must be painted on the outside to prevent rust.

Some smallish batteries have handles on the top. Very large ones like size 4D or 8D generally have handles on the ends and extra space must be left in the box for these batteries. Once installed wooden wedges can be used to prevent the batteries from shifting around while driving.

 

[danlash]

The angle makes up most of the frame and holds the battery securely in place and the round tubing and the all thread is the mechanism used to raise and lower the battery.

Wow dude, that is very cool. My friend's dad is a welder and sent me a quick design, but yours is next level (aka out of my reach ).

I think I'll have a go an angle iron based rack mount, and maybe use a car jack to raise/lower for maintenance.

 

[danlash]

We would be glad to work with a Promaster customer to verify this.

Very interesting, box looks very high quality. I'm sure blowing a fuse isn't super common, so having it outside the van isn't a bad idea. We're still in-progress deciding on load requirements, solar and shore design but if it matches up I'll reach out.

 

[Chance]

Not that it applies to me but I'd love to see images of a drop-in battery box. Very clever.

If I'm understanding what you guys call a "drop-in box" correctly, it should be a straight forward installation; although it probably adds cost compared to building battery supports out of angle iron. I have experience in this area with a large drop-in box and would do it again (and not just for batteries).

I've been saving pictures as reminders so if I build myself I'll know what the finished product should/could look like. The main challenge I see is how to cover the box area after battery is installed to make floor look finished.

This is one example -- I can only post one picture at a time.

 

[Chance]

With cover.

 

[Chance]

This one I really like, with multiple boxes.

 

[Chance]

And with multiple covers in place.

 

[danlash]

If I'm understanding what you guys call a "drop-in box" correctly, it should be a straight forward installation; although it probably adds cost compared to building battery supports out of angle iron. I have experience in this area with a large drop-in box and would do it again (and not just for batteries). :

Whoa those look great. I guess you would install all the flooring then cut a hole after so it remains seamless.

 

[Roblee]

My guess is the hole would be one of the very first things done. Then build around it. Looking seamless may be a priority for some but avoiding conflict with underfloor braces, cables, wiring, brake lines would be way higher. Then accessibility.