[corbin]

Hi all,
I just received my Thundersky batteries. I didn't order the copper bus bars or nuts/washers that come with them.

What kind of bolts and washers do you recommend using? I've heard from some people to use stainless (with NoOx goo), and others say to use steel connectors.

Should I use lock washers?

How long are your bolts that you are using?

thanks!
corbin

[dtbaker]

yes on stainless... with both AL and CU on terminals the stainless with noalox is a very good idea.

people seem to get by fine with the M8 bolts and lock washers usually, but I ordered a box of 30mm long set screws, nuts, and start washers because I kinda want to be sure I am getting full engagement all the way to the bottom of the blind hole.

I'll have a set of regular bolts/washers available in a couple days if you are interested to buy, let me know. I could price match a regular retailer and ship'em to you.

[corbin]

Originally Posted by dtbaker

yes on stainless... with both AL and CU on terminals the stainless with noalox is a very good idea.

people seem to get by fine with the M8 bolts and lock washers usually, but I ordered a box of 30mm long set screws, nuts, and start washers because I kinda want to be sure I am getting full engagement all the way to the bottom of the blind hole.

I'll have a set of regular bolts/washers available in a couple days if you are interested to buy, let me know. I could price match a regular retailer and ship'em to you.

Cool, thanks for the advice! I think I'll definitely use stainless. Where did you get your SS M8 bolts from? All my local sources are pretty lame (i.e.: OSH or Home Depot), so I'll probably have to buy them online.

corbin

[corbin]

And another question: I just realized that you probably are using threaded rod as a battery post, and then a nut on top with a lock washer; is that correct?

corbin

[dtbaker]

Originally Posted by corbin

And another question: I just realized that you probably are using threaded rod as a battery post, and then a nut on top with a lock washer; is that correct?

corbin

this is essentially what I am doing, except not just threaded rod. Set screws are socket-head, and can be tighened down all the way into that blind hole. the regular bolts have more or less engagement depending on stack height of stuff.... which can vary for the ones you put regular (thicker) cable lugs on, or if the holes are not all tapped the same depth. Going into soft stuff like AL and CU, I worry about over-torque pulling the threads out if not engaged enough.

Like I said, I will have a set of regular bolts and lockwashers available, or you can order your own stuff from somewhere like http://www.boltdepot.com

Shipping is a little high, but it comes out to about what you'd pay local retail, if your local people don't have boxes of stainless metric stuff.....

[Lordwacky]

I have to say that the set screw Idea is a damned nice idea... wish I had thought of that, I might just switch over to that setup. you should be able to tourque the nuts a bit higher with that configureation.

I recommend you using belleville washers in place of the standard star or Slit lock washer types. People seem to be having good luck with them on the forum.

[dtbaker]

recommended torque (per thundersky) is 20-22N-m, which is about 15-16 ft-#...

The place I bought hardware didn't have belville washers, so I went external star. I will probably put a drop of loctite on set screws, and use paint-pen on set/nut after final assy for quick visual inspections.

Next time around I may skip the factory multi-strip bus bars, and source some braided bus bars. They will probably cost a little more, but not tons would be my guess. My instincts tell me that terminals that are jiggling around between stacks of cells and moving a little with thermal expansion would do better with more compliant connections.

[EVfun]

Like this? I didn't like those copper straps that come with TS cells either.

I used stainless steel button head allen bolts. I covered my allen wrench with heat shrink so only about 4mm of the tip was exposed. Even if dropped on my battery pack it couldn't short anything out.

[Roy Von Rogers]

Use Nord-Lock washers.

Roy

[dtbaker]

Originally Posted by EVfun

Like this? I didn't like those copper straps that come with TS cells either.

what did the price work out to in USD for those braided bus bars from AU? I was poking around a couple weeks ago, and I remember finding some for about $7.50 USD, but I had already bought all my TS straps....