A123 battery Design 2.

OK so the last one was OK I thought but my problem with it was that before it was assembled on top of the cells it was just a bag of bits.  It’s better if the whole thing is pre-assembled and then when you come to fit it on the cells it’s just a question of tightening it.  I really don’t think you want to be there dropping bits in between the cells and fiddling around too much.  I’m also worried that when assembling it you could drop it at the wrong time and make a contact you didn’t intend.  I haven’t quite solved that problem yet though.

The colours represent the same materials as last time.

  • Light grey = A123 cell foil.
  • red = positive cell tab.
  • blue = negative cell tab.
  • dark grey = 1/4 inch thick aluminium.
  • pink/purple = screws / nordlock washers / nutserts.
  • light green = cast urethane with 2 nutserts in.
  • medium green = cast urethane with 2 drilled holes for the screws and 2 big counter sunk holes for the screw ends and nordlock washers.

Here’s the picture.  Click on it to enlarge it.

I’m not sure how easy from the picture it is to understand what’s going on.  Basically it’s the same as last time, but now the “U” shaped cast urethane pieces are facing the other way and the side blocks where the screws go are only half as tall.  The aluminium pieces have gained some tabs on each side and the tabs have holes in.  The screws go through the Cast pieces and aluminium and hold it all together.  I have decided to call the assembled thing a “cassette”.  The cassette’s interlock with each other, but to do that you have to turn one of them upside down.  Like the last design the only thing keeping the thing attached to the cell tabs is the clamping force coming from the screws.

This design is both better and worse.  It’s better to be able to pre-assemble everything, and I’m more confident you can exert a lot of force on the aluminium when you tighten the screws.  The problems are that it’s harder to make and the urethane blocks overhang the edges.

It’s a work in progress.  There must e a better way.  Onto design 3 I suppose.

[Disclaimer:  Just messing around.  I make no claim to  have  any expertise.]

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4 Responses to A123 battery Design 2.

  1. Mic says:

    Hi Nick, it’s an intriguing clamping system you have there.
    I read your comment over at EVTV. With the limited testing I’ve done, I found that a nylon nut on a nylon thread holds quite well. Having a way to hold the nuts on the ends of the module extra securely would be nice though. Unfortunately I can’t test the entire module design now because the person I was wanting to collaborate with was not sold on the idea of a DIY module.

    Hopefully these cells will remain available at a reasonable price and people will continue to work on their own designs and it will become the legit thing to do.

    • nickkkkk says:

      Hi. Sorry for not replying. I didn’t even know anyone read the posts I did on A123 batteries.

      I’m not an expert in anything. All I was doing with those designs was trying to find a way to modify Jack Rickard’s original design so that the clamping system didn’t take up so much space. He has since made many further designs. Some good and some bad. I think his experiments have been great to watch and he has hit on some better ideas. Anything I did is now redundant.

      Thanks for commenting.

      Nick 🙂

  2. piwhy says:

    Hello,
    That’s an interesting design to mount A123 pouch cells, but how do you integrate your BMS system with this design ?
    PY

    • nickkkkk says:

      Dunno. I wasn’t planning on making it. It was just me playing with an idea. I was modifying a Jack Rickard design. He wasn’t going to use a BMS.

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