Laser cut plywood deck with solderless 18650

This is probably not something you could expect, but I’m gonna try. I want to put all the batteries inside the deck without additional enclosure. Batteries will tightly sit inside and can easily be removed (airplane friendly). The deck might look thin and prone to crack but it shouldn’t because of the ribbed structure.

Idea:

  1. Laser cut 8 plywood sheets 3mm each
  2. Glue 7 of them together
  3. Insert 2x VESC + capacitors + wiring
  4. Insert 50 individual 18650 cells (without soldering)
  5. Attach the 8th plywood cower sheet with screws
  6. Put on hub motors

Laser cutting

Testing dimensions for one 18650 cell

Testing 10A current on solderless connection, copper doesn’t get warm

Designing deck around truck mount area

To be continued…

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Have you considered the affects of vibration and shock from cracks and bumps in the road surface on a solder less battery system. Possible loosening of the copper tabs and possible arcing at high current draw ? Sorry for the cloud.

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I have small silicone/rubber inserts under each copper tab, the battery sits really tight. 10s 5p will help lowering the current on each parallel group. I will start measurements at low currents first and slowly increase it.

Seems lit dude! So how do you cover the batteries then? With another sheet of wood? [quote=“rpasichnyk, post:1, topic:19005”] Attach the 8th plywood cover sheet with screws [/quote] So can you then see the batteries from below?

Subscribed! Want to see how this build goes. One thing I’m noticing is there doesn’t look like a lot of “meat” to the board, I think when you stand on it it might flex/break and move all your batteries - but it sounds like you’re aware of that and going to build it up strong! Keep us posted!

awaits eagerly with popcorn

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Ehm how can I subscribe?

I’ve been thinking about doing this for so long, but I have no where near the tools that I would need.

At the bottom of the thread

Then you’ll see this. Got it from there?

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Thanks! I also bookmarked it :sweat_smile:

Maybe a center chanel to route the balance wires

Are the batteries going to go in from the top or bottom?

Either way, you should match the 18650 curve on one side of the battery. So the middle sheet of plywood would be ~18.3mm then the next might be 17, then 16 all the way down to the cover.

Looking forward to the result!

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That looks very cool! It is a totally new approuch indeed! I am actually in the process of making a board of of @Maxid’s design. If you want it to be solderless you can also buy some battery cases from eBay like these:

Maxid’s board is also very nice (full credits to him!)If you want to fit more cells you can just make it longer… See a pic in the post below. I could only post one pic in this post…

Edit: I somehow am not allowed to post the pic… you will have to ask him for pictures…

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wonder how strong that wood will be with most of it gone. gluing the sheets how will you put pressure on them?

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Uh nice - let me know how it turns out!

http://www.ebay.com/itm/Plastic-Battery-Holder-Storage-Box-Case-For-4-x-18650-Rechargeable-Battery-US532-/322446693884?hash=item4b135215fc:g:QSgAAOSwr2RYKSO2

I think these are the same as what you posted there but let me know if you have a better link :slight_smile:

Looks really good!

I really like the idea. This might be my next upgrade if my board turns out well (really love ultra thin designs with minimal components protruding). Also regarding the strength of the board since some people seemed concerned; I’m not sure if you’ve run an FEA on it, but given how thick the board is gonna be (about 2cm thick right if you’re fitting 18650s in it?), and the fact that both the top and bottom are solid plates, it should be really strong since you’re greatly increasing your moment of inertia on your board (these might be unfamiliar terms, this is stuff I’ve studied, mechanical engineering: beams and bendy stuff). In any case, for the same reason and I-beam is strong, this board should be really stiff and even stronger than a regular board load-wise. Haven’t run the math so this is just an opinion, but an educated one at the very least.

In any case awesome project, and do post updates!

EDIT: but since you’re doing laser-cutting you might know about all this stuff, but for the others: his board is cool

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Don’t think they will hold the current

looks interesting. but with a flat deck you feet will get sore before you can run out 50 cells… can we get a zoom out on the deck? I would add another cm to each side. since thats where most of the strength will come from.

also consider staggering the battery cells for a more honey comb like structure.

The bottom one looks like the same model. Remember that you want as much metal contact with the battery, so the model with the springs is probably not going to work well… It will probably get very hot due to high resistence. You should also get some thick wires in between the cases as well :smiley: