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Dan Lenox
28th January 2008, 09:41
All,

I had been looking for a while and it seems that most of the battery trays/chests made are for commercial use, and pricing is out of my range.

So - I designed and built my own. I worked with my good friend Paul Schreiner (of PS Composites) and we designed and made a mold for my battery trays.

The tray dimensions are basically 24" x 31" and can hold up to six #31 sized batteries. We also designed the trays to have the capacity of slightly over 2 gallons of capacity, this way if one or more batteries rupture the battery acid is contained.

Here are a couple pictures of one of the trays:
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I decided to have mine colored green (as this is a green project) but Paul can make them any color you want - even metal flake! Next on my job list is to make a simple wood chest and a pexiglass top to contain the batteries.

I will be using two trays, and building a simple wood chest and pexiglass top to contain them. In addition I will have the chest vented using a fan.

These trays are a good starting point for building a chest, if you are interested in purchasing any give Paul a call, his phone number is on his website.

I have no affilliation with PS Composites - Paul is a good friend of mine.

I also came up with an easy/consistant way in which to solder up the lugs onto heavy #2 cable, and made up all of the battery interconnects and cables. You can save yourself a bunch of money by making up your own cables.

The cable that I am using for the battery inter-connects is a #2 S/O stranded copper wire, it is very flexible and bends easily, it is widely available as cable that is used for welding, our local Tractor Supply carries it. When making your cables you want them to be as short as possible, but you also don't want the cables pulled straight and tight either, leave an inch or so extra to give them a little slack.

If you do decide to make your own I have learned that there are two kinds of soldering flux available, one which is an aggressive flux that states that it should not be used with electrical connections. It looks like the 'standard paste flux' is not an agressive flux and should work fine for use here, so be sure to read the label that is on the flux so that you use the right one!

With some experimenting I discovered that if you applied soldering flux to the inside of the lug (and on the cable) along with 5 lengths of solder (about .050" diameter) that it works out quite well. Four lengths did not seem to be enough solder to properly do the job.

The first photo below shows the lug filled with solder, it is held in place using some vise-grips:
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Next using a propane torch heat the lug until the solder melts this should only take about 10-15 seconds, if it takes longer then you are not using enough heat. Once the lengths of solder have melted into a pool, remove heat (mainly so you don't burn your finger tips) and put the prepped end of the cable into the lug but do not push in yet! You have to apply more heat to the side of the lug, you need to do this so the lub and the cable can get to the proper temperature. After about 10-15 seconds or so push down on the cable twisting it into the hot bath of solder inside the lug. Once the cable is in, continue to heat for another couple of seconds so that the solder works it's way all through the cable strands and then you're done!
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Cool and wash off the excess residue of flux and clean the surfaces with a rag, finish off the cable ends by using some lengths of the proper colored heat-shrink tubing:
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To be continued...
Dan Lenox

Mark Parsons
28th January 2008, 20:08
Greetings Dan,

I used a deck box to house my batteries. Since it is in the unheated garage, I lined the interior with 2" SM styrofoam to help keep the batteries a little warmer than ambient average.

deck box examples - http://www.rubbermaid.com/rubbermaid/product/product.jhtml?prodId=HPProd100689

The size I have fits up to 8 Surrette S530 batteries. It also has a tray section in the base that would hold at least a gallon of battery fluid upon the unlikely event of a leak or rupture.

I will plumb a vent pipe in when I get the garage sealed up.

Very good tip and technique for soldering copper cable lugs. Are the type you're using made to solder? Most cable lugs I run across are compression type. They need to be crimped with a controlled cycle tool.

Regards,
Mark

Dan Lenox
29th January 2008, 07:22
Mark,

I think that commercially people do not solder now days, it is quicker and easier to crimp them rather than go throught the bother and expense of soldering. I have seen some references that some electrical codes somewhere state that even if soldered they still need to be crimped.

I did not want to spend $150+ on a crimper, even though I could have devised something to work in a vise.

You have to really get the insides of the lug clean using some sand paper, but that is standard practice when soldering to copper. For a little extra money you can also purchase lugs that are pre-tinned, and they certainly beg for soldering...

Good reference for use of deck boxes, I would never have thought of them! Looks like the sized box you refer to sells for about $120.

Dan Lenox