DIY BUSBARS

[HRTKD]

Yup....that is what I use. Unfortunately the copper gums up the file rather quickly..... Does anyone know how to easily clean the soft copper off the file?

Wire brush?

 

[Zwy]

It was fun the first time. Interesting the second time. A chore the third time. If solder-plating wasn't so much easier I would still do the electrolysis.

I thought it was easy enough as it was. Once you have the solution made, it's just a matter of dipping the item into the bath for 30 seconds per side or even twice if you want thicker plating. I want to thank you for taking the time to put up the info.

 

[Q-Dog]

Yup....that is what I use. Unfortunately the copper gums up the file rather quickly..... Does anyone know how to easily clean the soft copper off the file?

The tool you are looking for is called a file card. It is an extremely fine brush specifically made for cleaning files. For a course file you can use a wire brush. Also, a small wire wheel chucked up in a drill press at low speed is really handy for cleaning all sorts of metal objects and tools.

 

[cinergi]

I just drilled 5/16" holes and used a center hole punch to mark where the hole should be and a cheap drill press. The bus bars all fit amazingly perfectly and I'm not concerned (and haven't seen any reason for concern) about using a 5/16" hole vs 1/4" in terms of loss of surface contact. These are even bus bars that are 4 terminals long (2 cells in parallel)! I stood the bus bar up against the 4 terminals (with studs inserted) and used a marker at the top-center of the stud to mark the location along the piece of copper. I then punched a hole in the center of the copper at that location.
Brand of battery and your fixture will make a huge difference. Lishen's don't appear to expand and contract but Eve's expand and contract a lot. Even if my pack (EVE cells) was fully compressed at 100%, if I break the pack open and recompress it, the bus bars do NOT line up. I have to discharge the cells first.

 

[Robert470]

Would I have any problems using 1/8” thick 1” wide aluminum flat stock for busbars, it’s almost twice as thick as the ones that come with the batterie??? Or should I make some up using 4 gauge wire with lugs at the ends???

 

[time2roll]

Aluminum has 61% conductivity compared to copper. (google) It would seem if you are swapping copper for aluminum you would want them twice as thick. With studs is probably fine but a screw will lose some thread contact that already seems marginal.

 

[Robert470]

Aluminum has 61% conductivity compared to copper. (google) It would seem if you are swapping copper for aluminum you would want them twice as thick. With studs is probably fine but a screw will lose some thread contact that already seems marginal.

So, seeing that they’re almost twice as thick as the busbars that come with the batteries I should be ok with using the studs that came with them??? Later on I’ll be replacing them with copper bus bars but at the moment aluminum is all I have. Or should I double up on them??? What about making up my own using 4 gauge wire with copper lugs at the ends???

 

[Topper]

Copper 1000 Amps per square inch
Aluminum 700 Amps per square inch
Brass 250-300 Amps per square inch.

Actual amps vary depending on specifics of the material. These numbers are a reasonable enough quick guide reference.

 

[HRTKD]

Don't size the bus bars based on the old bus bars. The old ones may have been undersized. Figure out your maximum amp load and size the bus bars for that. There are reference tables that define the number of amps that a cross sectional area can handle.

 

[Freep]

Don't size the bus bars based on the old bus bars. The old ones may have been undersized. Figure out your maximum amp load and size the bus bars for that. There are reference tables that define the number of amps that a cross sectional area can handle.

And it doesn't hurt to make it a little bigger than the reference table states.

 

[Positronium]

It was fun the first time. Interesting the second time. A chore the third time. If solder-plating wasn't so much easier I would still do the electrolysis.

Electroplating is not necessarily needed to tin copper. It is still requires the hydrochloric acid to make aqueous solution of SnCl2. An alternative is to buy the anhydrous SnCl2.

 

[Bob B]

AHHHH .... Redox flipping .... of course.

 

[Dynoman]

I am looking at some Extruded Aluminum 0.25" x 0.75" Rectangle Bars 6063-T52 to make bus bars for Lishen 272ah cells in 4s for 12 Volt Batteries. Has anyone successfully used Aluminum stock like this to make bus bars? Would this be enough aluminum mass to handle the current?

My plan is to run aluminum bus bars on the cells and connect to the BMS & junction posts with tin plated copper wire lugs with a little DeoxIT DP5 on the connections to help with corrosion.

I will have a total of 16 cells to make Four 4s 12 volt batteries.

Any thoughts would be appreciated...

​

 

[Hedges]

Yup....that is what I use. Unfortunately the copper gums up the file rather quickly..... Does anyone know how to easily clean the soft copper off the file?

 

[schmism]

These are mine.

Cut the 1/2" copper tubing with a tubing cutter, pressed flat with a 20 Ton press and tuned up with a smooth hammer and anvil. Drilled on the drill press with a 135deg (metal) drill bit.

 

[Ironman]

Before you start to file, take a marking soapstone and fill the file teeth with the soapstone. Then to clean, you can wirebrush the file and redo the soapstone.

 

[upnorthandpersonal]

Electroplating is not necessarily needed to tin copper. It is still requires the hydrochloric acid to make aqueous solution of SnCl2. An alternative is to buy the anhydrous SnCl2.

Or nickel plate them with nickel acetate. Only needs two bars of nickel, vinegar, salt and the power supply.

 

[2Big2B]

I just made a couple of sets of copper busbars from solid flat mill Bus Bar Stock that I found on ebay for about $12 each per 14" long bar. That is long enough to carve out about 8 bus bars. Aluminum bar stock works too, but it only it has 61% conductivity compared to copper.

(The bar stock I used is a bit thicker than it needs to be, but it is a matter of compromise finding the best fit of what is available. What I used worked well for me. I found the eBay listing: "3/16" x 3/4" C110 COPPER BAR 14" long Solid Flat Mill Bus Bar Stock H02 99.9% CU. Seller: "6061dude" Free shipping was fast, coming from Colorado Springs, Colorado, taking only took a couple of days to Virginia).

The first thing I did was to line up my cells so that I could measure the size and spacing of the finished busbars. I then took some card stock and cut out templates of an ideal busbar, fine tuning the holes for the terminals and lengths. I then tested the paper template across the terminals of my configuration and, once satisfied, I took a black magic marker pen and drew out the pattern on the copper flat bar stock. Making a dry run with cardboard bus bars is a great safety measure too that prevents some stupid mistakes.

I then clamped a scrap piece of 2x4 wood to my table. Clamp one end onto the copper bar stock to hold it in place while drilling a couple of holes in the pattern drawn on the bar stock. Then using a couple of screws to nail it down to the 2x4 it becomes a jig. Drill the rest of the holes with a good strong hand held electric drill. I broke and dulled some drill bits doing this - so you might want to start with pilot holes and have some spare bits at hand. I elongated the holes side to side with the drill for better adjustment when mounting the finished bus bars later. I also then raked my drill horizontally across the flat of the bar to scrape away any burrs created around the holes.

I then remove the screws and move the bar forward toward the table edge for cutting. Once positioned I screw the bar back onto the 2x4 (clamped to my table) for stability. I then use my good old Black & Decker hand electric jigsaw, with a metal blade, to cut off each piece, removing and replacing wood screws along the rail as I progress.

I found that this metal is tougher to drill and cut than expected. Have spare jigsaw blades handy and wear eye protection. But the real trick to it is to put some oil on the blade and cutting surface when sawing. I used a spray can of Liquid Wrench Penetrating Oil I had handy. It made a huge difference.

 

[kromc5]

Copper plate depending on you amp requirements is not to expensive, the thicker plates have greatly increased. I'm using a bevel saw with carbide blade and drill press. These are all 1 inch by .25 and 3 inch by .25

 

[2Big2B]

It's nice to have the right tools! I was able to make do with what I had. If I could have taken it somewhere to have it done inexpensively I would have. These days that probably will never happen though. So, a hand drill, hand jigsaw, a strong table, big clamp, a piece of scrap 2x4 and some imagination get's her done!

I think to cardboard cutout templates was my best brainstorm though!