NCV3 house battery tray design & group buy?

[hein]

Good Morning,

I'm working on a tray for two 6V house batteries to mount under my 2010 NCV3 170WB 3500. The location is along the side in front of the rear wheels. I can put 2 batteries on each side and they will hang below the bottom lip of the van body by only about 1".

I have the tray mostly designed. It is basic so there is no provision to lower or lift the batteries. The tray with batteries will have to be lifted into place with a floor jack. The hangers stay on the van. I could design a lift but it would add significant cost. Not out of the question, though.

I am currently looking for a fabricator in the Portland, OR area who can build the assembly. I will likely make some tweaks to the design and still need to design a cover for the batteries.

Questions:

1. Would there be any interest in having more than the two I need built?
(I'll post up a cost estimate later)

2. Does my design fit a 114 WB van? Would need someone to check some dimensions.

Pictures:
The spot: (drivers side shown, passenger side is the same)

The tray:

 

[Legwound]

Timin is good for me. I'm looking into batteries/charging etc and have been following the hosue battery charger thread.

Anyway battery placement/tray design is on my to do list. I have a 2010 144 and am looking for placement and mounting ideas. After reading the HandyBob link in the conversion sticky I'm thinking either 2 or 4 Trogan 6 volt are the way to go over AGM's. Jury is still out for me on that, more reading. Regardless I'm interested in mounting and placement.

I have a concern on lack of access from the top for battery testing/watering and cable hook up access. My initial thought is access tom the top of the batteries while in place for maintenance is desirable.

 

[chromisdesigns]

Timin is good for me. I'm looking into batteries/charging etc and have been following the hosue battery charger thread.

Anyway battery placement/tray design is on my to do list. I have a 2010 144 and am looking for placement and mounting ideas. After reading the HandyBob link in the conversion sticky I'm thinking either 2 or 4 Trogan 6 volt are the way to go over AGM's. Jury is still out for me on that, more reading. Regardless I'm interested in mounting and placement.

I have a concern on lack of access from the top for battery testing/watering and cable hook up access. My initial thought is access tom the top of the batteries while in place for maintenance is desirable.

You really can't use a mounting tray like this with anything except sealed batteries. Just won't work for flooded cells, you HAVE to be able to check electrolyte levels and keep them watered. AGMs are perfect for this kind of mounting system, though.

 

[GeorgeRa]

On my trailer I had 2 out of 3 flooded batteries with very limited access and used the semi automatic water filler gadget. Worked well. http://www.campingworld.com/shopping/item/qwik-fill-single-12-volt-battery-watering-system/27038. See no reason why this would not work in this application.

George.

 

[hein]

Thanks for the replies and insights.

I spent the afternoon at Northwest Battery Supply measuring actual batteries, 4/0 cable bend radius and Magna lugs so I can verify the actual wire routing in CAD. Once I do that I can add features to the tray to locate and secure the batteries. I've heard that putting a foam pad under the batteries is a good idea so will include that.

I was intent on AGM but was also impressed with the watering systems that are available. There is 2" of head room so plenty of space.

-Hein

 

[chromisdesigns]

On my trailer I had 2 out of 3 flooded batteries with very limited access and used the semi automatic water filler gadget. Worked well. http://www.campingworld.com/shopping/item/qwik-fill-single-12-volt-battery-watering-system/27038. See no reason why this would not work in this application.

George.

Interesting. Haven't seen those before. However, you would never be able to check specific gravity without unbolting and jacking down the tray. You should do so occasionally with flooded cells. http://www.trojanbattery.com/batterymaintenance/testing.aspx

Also, you won't be able to tell which batteries and/or individual cells are actually using water, which is another indicator of battery condition.

 

[hein]

Checked the 4/0 wire routing and updated the design so the tray can be dropped for maintenance.

up:

down:

 

[tDot]

I'll be following this thread with interest. I was just starting the think about designing a tray for AGM's to go behind the wheels of my 2012 3500 144. But if there is an option to install them in front of the wheels, I'd be happy with that too. And if I could revert back to FLA's, if there was an easy way to monitor them, that'd make me even happier.

 

[RonR]

Nice concept and nice drawings.
I'm in the middle of my own design. I considered hanging the batteries but finally went back to the design in my current conversion. I had cut a hole in the floor, build a box (with a vent) to hold the batteries and load / maintain from the top. A screw on cover with gasket keeps the dust out but still allows access. I fabricated the box out of .065 aluminum sheet and pop rivets. Still looks good after 10 years. (you could raise the height of the cover if you need extra room). Of course, it doesn't help if you can't get to the top but it did work for me and is the plan for my second build. I travel some rough roads and heard the batteries bounce in the first few weeks of use. To prevent any chance of a short circuit I placed foam blocks on top of the battery (no chance of bouncing and touching the frame / floor).

Two comments on your current design.
You should insert some sort of a spacer / filler next to the exposed / welded nuts to prevent any chance of abrading a hole into the plastic of the bottom of the battery.
If you rotate one of the batteries the connecting cable (battery to battery) can be shorter and would not need to cross over the other cable. It also would be slightly smaller. Per your drawing (right side) there is a chance of pinching the cable with a potential of eventually rubbing through the insulation.

Good luck
RonR

 

[hein]

Thanks for the reply, ideas and comments. I'm still working on some of the details and there are some aspects of the design that are not readily apparent.

The batteries will be fully constrained by spacers or cross members on each side and a hold down system - probably J-bolts with a bar across the top of the battery. The tray will have a plastic bottom plate with a foam cushion and there will be a vented plastic cap for the top of each battery.

The batteries are oriented and cables routed in that way to avoid the frame cross member between them. (shown in the first picture) I plan on running the cables inside nylon sleeves to protect from chaffing and have accounted for the added diameter in the CAD. I am using a generous bend radius so hopefully my actual routing will be somewhat better.

The inverter will be almost directly above the passenger's side battery bank so wire length on that side is really short. The battery bank on the opposite (driver's) side is still close enough to keep the cables under 10ft.

I'm almost ready to make a prototype and hopefully share more details and some pictures. I stopped by the battery place today, got an empty 6V battery shell and held it up there to make sure it would go. Looked really good actually.

 

[icarus]

Regardless of anything else, I would include a BlueSea fuse on the batteries given thier location. I would also install a Bluesea series fuse. In the case of of a a shorted cell in one battery, the series fuse would prevent a thermal runway, and since you can't easily access the batteries and thier terminals fusing is never a bad idea.

Icarus

http://www.bluesea.com/products/category/Fuses/Marine_Rated_Battery_Fuses

 

[hein]

I am considering a fuse on each positive terminal (is that overkill?) and a larger breaker/disconnect prior to the 12v distribution panel.

 

[GeorgeRa]

I am evaluating all options for my battery pack on 144". One of the options is to place either group 27 or 30 flooded deep cycle (perhaps Trojan) battery under the van working in conjunction with OEM deep cycle flooded battery from under the hood. I could use some components of your design to adapt to my single battery tray. This combination would give me 200-205ah.

Regarding welding, I used very successfully JD Cross http://www.jdcross.com/ from East Portland. Recently they welded for me 2 SS water tanks and did excellent job. For powder coating I found Tufcoat in Tigard at a reasonable price. Recently they coated all steel brackets for SS tank mounts. http://www.tufcoat.com/drivingdirections.html

George.

 

[hein]

Thanks for the the fabricator links. I'll check them out. I am scheduled to have one of mine built in about a week. I did look at having most of the the parts laser cut. I really need to update the design to take full advantage of that although it does help to have a set of highly accurate parts that just need to be welded. Cost is a little high for just one or two trays but if we can add quantity than that will really help bring that down.

If you can give me some dimensions for your battery and the place you want to put it, then I can update the design accordingly. I have a fully detailed drawing that you can give to your fabricator. You can make some cardboard templates to test the fit beforehand. The overall length between the hanger legs matches the distance between the cross members on the van. The height is determined by the battery case plus clearance for connections. On my van the hangers are slightly off center because I need to miss a gusset on the frame. That's not necessary in the rear.

 

[GeorgeRa]

Yesterday I purchased 2 Fullriver group 31 deep cycle AGM batteries and will no be pursing under the van option. If you would decide to design a single battery tray than than I would suggest either 27 or 31 group. Good luck.

George.

 

[hein]

I'm planning on some Fullriver GC2 AGMs from NW Battery. And since I won't need to check them, I'm going with a simple stow-n-forget battery tray.

 

[mean_in_green]

I'm a little surprised that more owners haven't cottoned on to the storage potential which exists underneath the Sprinter, there are several recesses that would lend themselves to more projects like this one. Probably the best height to be adding weight too.

 

[GeorgeRa]

I'm a little surprised that more owners haven't cottoned on to the storage potential which exists underneath the Sprinter, there are several recesses that would lend themselves to more projects like this one. Probably the best height to be adding weight too.

In my 144" under floor cavities are well utilized. The left cavity contains 15L Isotherm water heater and 14 gal SS grey water tank and the right cavity houses 12 gal fresh water SS tank. My DEF tank is in the engine compartment.

George.

 

[hein]

Not being able to leave well enough alone, I worked up a drop tray. Now to decide which to build. Still going with AGMs but the ability to drop them down is kind of cool/convenient. Not all the fasteners are shown but hopefully you'll get the idea:

 

[barberja]

What are the dimensions of the tray? I would like to see if it fits under my 2013 170 Crew 2500. You could see if a roll form company can make them for you. There are some fabricators in Denver that would take on the project as well. I would prefer less moving parts but that's just my preference.