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© 2017 Ian Watts

Final Packaging

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Various options exist for packaging the final cell-pack;

  • simple tape (of various sorts)

  • heat-shrink

  • bespoke / custom made / purchased

  • 3D printed...

or a combination of some or all of them.

In my case it tends to depend upon various factors;

  • the size and shape of the pack I'm creating

  • the use the pack is being put to

  • any additional components I wish to include with the pack

  • the environmental protection the pack will require

I am lucky enough to have a fantastic 3D printer and to have spent many hours putting Sketchup to good use refining my design skills. I tend to favour 3D printing to create bespoke housings, brackets and other bits'n'bobs I require.

Example 1:

A 4P pack I designed and made to wirelessly charge my mobile phone.

The 4 cells are connected in parallel and each one has its own BMS.

Because the cell-'pack' resides, snugly, within a 3D printed box / enclosure, no additional protection is required.

The left-hand image shows the 4P battery holder. 4P - 4 sells in parallel.

There are THREE wires becaue the BMS units are of the split-port type; the thicker red/black are for the power o/p connections and the thinner blue cable is the charge -ve (charge +ve connects directly to the thicker red)

The right-hand images hows how the underside of the pack was designed to allow the BMS units to fit in-between the batteries and connect to a pair of common +ve / -ve 'rails'.

A 3S pack I intend to use to provide 10V - 12V for the scoot project.

Example 2:

The pack will be tie-wrapped down and won't be able to move.

Apart form the BMS there are no additional components to mount or protect.

It should be in a relatively water-free environment.

Once assembled (with the BMS) it was wrapped in 3mm foam and heat-shrunk in both directions.

The 'end caps' I designed and made to finish the 20S4P packs I intend to put to use on the scoot project.

Example 3:

This particular 'build' required both 3D plastics for the end caps and the CB housing and then heat-shrink to bind the finished pack together once protected by 3mm foam.

The ribs around the ends of the end-caps are to provide enough 'grip' for the heat-shrink to keep the pack together longitudinally.

This pack was designed to be modular - the idea being that it should be readily removable for charging and security and that it would function equally well as a single pack for an ICE to electric lawnmower project AND in a parallel configuration for the scoot project. In both cases, 'long and thin' seemed to fit my project design expectations... we'll see how things pan out... 

With a little more time being spent with the scoot and my decision to run with a mid-mount motor I may yet change the design due to length constraints and my hopes to keep the under-seat area free for a helmet (probably pie-in-the-sky by the time I get a charger on board as well.

This long'n'thin design does, however,  suit the lawnmower project where it sits across the width of the mower just behind the motor...