[RE-wrenches] Battery Box Construction

[Luke Christy]

Hi Shasta,
I have to second Ray and say that I'm impressed with the description of the battery boxes you've been making. I've always been dismayed by wooden battery boxes as well, but I have installed a lot of them, both because of the ease of getting materials and because they do seem to hold up fairly well over time. 

I'd like to make a move away from them though, and I'm intrigued by your take on construction. 
Are you using Stainless angle and u-channel for holding plastic panels together? How do you make the box rigid enough with only 1/4 thickness plastic sheets? I guess maybe the rigidity is coming from the angle and u-channels?  What is the non-corrosive/conductive  coating that you are using for metal pans (made of mild steel, I assume). Just curious.

-Luke



Luke Christy 

NABCEP Certified PV Installer™: Certification #031409-25 (Luke Christy)
NABCEP Certified Solar Thermal Installer™: Certification #ST032611-03    
 CoSEIA Certified PV Installer (Luke Christy)

Solar Gain Services, LLC
Monte Vista, CO.
SGSRenewables at Gmail.com

On Jan 29, 2016, at 10:08 AM, Shasta Daiku <mjmorningstar at gmail.com> wrote:

> I have always been dismayed with wooden battery boxes used in professionally installed power systems. It seems vey DIYer/HomePoweresque. Where else is wood used in electrical installations? I have on occasion built some BB plywood core boxes, sheetmetal outer skin/ FRP inner skin/ raw edges and corners banded with SS angle/ rubber gaskets with lots of latches.
> 
> I build boxes that are made of either plastic or metal depending on the environment and usage they’ll see. Plastic, that is HDPE or acrylics, I order online cut to size, or from a glass shop. 1/4” thickness. Metal, heavy gauge sheetmetal, I have cut by fabricators, and then coated with non-corrosive/conductive coatings by a cabinet shop.
> 
> Here are some general guidelines
> 
> -With either material, I keep the panels sized small. Less than 2’ x 2’ is nice, both for shipping and handling. 
> 
> -Panels can be attached to each other using H and U channel, and angle stock (which also gives rigidity). Lids are usually sectional rather than a heavy 
>  single lid. Sometimes, on plastic lids I rout rabbets on the connecting seams so that the there is a half lap joint.
> 
> -Plastic can be drilled and tapped. I generally avoid using adhesives because they are toxic as Hell and pieces want to slide out of alignment.
> 
> -When batteries sit on metal racks, I enclose the racks with acrylic sheets using rare earth magnets. Magnets are attached to the acrylic with epoxy or the 
>  magnet will have a counter sunk hole and machine screws can be used.
> 
> -I seldom build a box with a back wall. Instead, I apply a sheet of FRP (fiberglass reinforced plastic) to the wall that the box sits against, smooth side out.
>  Side panels butt against, and are attached to the wall using U channel or angle stock. This accommodates a wall that may not be flat or a 
>  wall/floor intersection that isn’t square. Corners, That is sides to front pieces are made with angle stock. They knock apart by using wing nuts or 
>  magnets. That way the front of the box can be removed for placement/replacement.
> 
> -I stopped using hinges for lids along time ago, when I started making lids that were sectional. Lately I run a length of U channel against the back wall, the 
>  length of the box. The width of the channel is wider than the thickness of the sheet, so that the sheet will slide in easily. The lid section is removed rather 
>  hinged up. You know the saying “Don’t let the lid hit you in the head!"
>  
>  -Over the years I have tried a lot of coatings in my metal boxes. All have held up well, but I have found that engine compartment type undercoatings to be
>   my favorite.
> 
> -If I have a say in the power room/shed design, I will specify a concrete slab with a shallow basin for the batteries to sit in. The basin has a floor drain and is epoxy coated. Otherwise I have a sheetmetal tray fabricated and have it coated. The tray is separate from the enclosure.
> 
> 
> -In very hard use applications I have the box made by a company that outfits utility and work trucks with beds and boxes. These are just large custom
>  “truck boxes” 
> 
> -With smaller banks, I have successfully retrofitted both gang boxes and truck/utility boxes. The simplest setup being adding some cross members to a  
>  $300.00 gang box so that the batteries sat elevated within. That makes a very nice servicing height! Again interiors are coated.
> 
> Growing up, I had a lot of exposure to both industrial off-grid power systems (mining, oil/gas, research, telecomm) and Maritime systems and thats
> where my sensibilities originated. Lately I have found myself the sole off-grid specialist in a fairly vast area, and so what Im doing mostly is replacing battery banks. Lots of battery banks, and lots of rotten, corroded, nasty toxic boxes! A few weeks ago my helper and I donned Tyvex suits, rubber gloves,
> goggles, and respirators to Demo a box that was in a dilapidated and soon to be be razed structure. The general contractor and client stood by laughing and commented that it looked like a scene from Breaking Bad!
>