Build in a toolbox, tight or roomy?

[hwy17]

I'm planning to build my 16x304 bank in a tool box, side opening.

The bank will be like 23"x14"x9"H in a half length config. Without the compression gear.

I'm looking at two toolboxes:

24x16x14H

24x18x18H

My gut is telling me get the roomier box, but it would be nice to have a tighter config for space in my tiny utility room.

Any thoughts? I think this is one of those moments where I already know the right answer. Make it easy, get the extra room. But my head is telling me small is nice.

 

[hwy17]

The question would be whether I door mount the BMS and contactors, or "ceiling" mount it. Door mount is probably not possible on 16" and I know ceiling would be such a PITA.

 

[42OhmsPA]

Roomier gets my vote. I was cursing myself installing the BMS and Class T in my tight rack/shelf I built.
It will be way easier to add 'filler' to take up space than create space... I'd also plan to use a quality flexible wire.

 

[hwy17]

Roomier gets my vote. I was cursing myself installing the BMS and Class T in my tight rack/shelf I built.
It will be way easier to add 'filler' to take up space than create space... I'd also plan to use a quality flexible wire.

For the big stuff or little stuff? I'm considering ordering some silicone 18ga for littles.

I guess you must mean big and yeah it's probably time for me to consider a crimper so that I can crimp stuff in shape.

 

[42OhmsPA]

For the big stuff or little stuff? I'm considering ordering some silicone 18ga for littles.

I guess you must mean big and yeah it's probably time for me to consider a crimper so that I can crimp stuff in shape.

The big. For example I used 1 awg marine wire (I had a bunch left over) for my pack to buss bar connections. It was a pain to work with in comparison to the 2/0 welding wire I used for the main inverter connections.
I've been pleased with my temco on 4awg - 2/0. My only complaint is the number of crimps they give as a guide is way off, it takes a few crimp and check to get used to.

TEMCo Hydraulic Lug Crimper Tool TH1818 DIELESS Indent 10AWG to 400MCM Electrical Battery Terminal Cable Wire 5 YEAR WARRANTY https://a.co/d/7kTkuVk

 

[SamDeleted]

Tight is always my preference, but each to their own ?

 

[740GLE]

You have a link to the tool boxes?

I’d be more concerned about weight capacity of the tool boxes being able to support a 16x280ah build

 

[hwy17]

Yeah it's a good point, I'm hoping it's truly flat bottomed but I can't find any pics of the underside. First one would go on the concrete floor. But I also had in mind that I might stack another one on top and bolt them together for a second battery. Otherwise it would be easier to work with a top opening.

https://www.buyersproducts.com/product/white-steel-underbody-truck-box-33

 

[hwy17]

I'm considering now that my separate charge and discharge circuits system design requires that the contactors be master contactors located outside of the battery box. At which point maybe the BMS should just go outside too since I'll be wanting to get at it's serial port often anyway, and then the battery box is really just a container for the cell bank only, swinging me back towards a tight fit.

Still that nagging feeling that I know tight working space with a dangerous battery is a mistake.

 

[Brett V]

My first toolbox build was a string of EVE 230 Ah cells stuffed in a 38x13x10 toolbox, wall mounted with front opening. The BMS was against one end so everything was contained in the box. It was tight but worked out well and looked good. I had no problems for the 18 months or so I had it in operation.

The second build was two strings in a 48x15x15 toolbox. It was top opening and on wheels. The build had much more room and was a lot easer to work with. https://diysolarforum.com/threads/new-battery-in-a-toolbox.62347/

 

[hwy17]

@Brett V Did you build the second pack out of all new cells or did you parallel your old with new? Or it's not 16s2p but 2x 16s in one case.

I take it from the fact that you went roomier with the second one that you wouldn't go tight again, even after you did make it work?

 

[Brett V]

I paralleled new cells with the old ones, no problems at all. In fact I'm now up to four batteries of three different purchases, all the same EVE 230's and it's working well. Everything I've built is a single 16s with its own BMS.

Battery Rack 3.0 Almost Complete

This is my third and final ;) DIY battery revision, the first two were contained in a metal truck toolbox. Went a different route here to repurpose my old Power Conversion (Eaton) lead battery rack and distribution panel. The bus bars are rated at 600 amps, spaced and supported on fiberglass...

diysolarforum.com

The first battery box on the wall was tight but I would do it again simply because it looked so good. I had about 2 inches between the top of the cells and the underside of the box so checking the connections was a bit tricky, but it's not really something that requires maintenance. My decision on how roomy the second box was had more to do with the box sizes available.

 

[hwy17]

Everything I've built is a single 16s with its own BMS.

I was previously considering paralleling a 16s1p into a 16s2p on a single BMS in the future. But now that I've accepted space constraints in my placement I won't even have the option anyway.

With my space constraints, basically about the size of an electrical panel working clearance area, the smaller box is going to pay off pretty well.

Maybe I go smaller and spend the extra for some truly insulated wrenches: https://www.amazon.com/KNIPEX-98-00-10-Insulated/dp/B005EXP8AA/

 

[740GLE]

2 wraps of electrical tape on an adjustable is all my cheap ass will get. That does look mighty nice though.

Safety third!!