Trampa ub battery build. Molicel/VESC/D140

I’d like to share some battery building with some new builders. This will be my first under-board battery tray so constructive criticism is welcomed from experienced builders. I stress safety as a main concern whenever dealing with electronics this powerful. As no one Ive found has a pack or flex design similar to this, i have no blueprints to work off. Onto the goods.

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I am planning to build a 12s4p with Molicel p42a’s, if space allows. Bought 4 extra cells for other fun stuff. Trampa order should arrive soon and i will list the maximum inside dimensions of the tray from left to right and bung to bung.(aluminum endcaps of the tray) If I have to mount the speed controllers and BMS topside I will, but the goal is to stow them all away. Ill also be updating my holypro deck to accept TRAMPA wings. Ill post pics of that surgery as well.

Got the trampa order early!

Trampa’s usual homemade packaging!

Battery tray dimensions. Inside. 24"x6"x1" rough.

no pic of depth but it does appear to accommodate 21mm plus some padding. Ill install the wings and tray first as they require modifying the deck. Get the messy stuff out of the way. Trampa gives you wingsssss!!

Good news, batterys are here, and look to fit in the tray. :ok_hand: Wings are installed.

I would have liked to space things more, but that will do pig.

Its a tight betty.

But we can make it happen, cant we ladies?

Taping and welding the 4p packs with a small tape divider.

I chose to use mountain dew and other pop bottles to add insulation where a short is possible.

I also had some cardboard dividers. If i had more bottles id have used those, their thinner and less friction, but I try not to drink so much soda! So i used a laundry detergent bottle as well.

This is where things get sus…

Crossing the nickel at a slant across the top of the packs. This way i could spread the nickel strip to lessen the stacking for a smaller pack, only way I could fit this big boy in there. Also it allows the welded connections to avoid stress by taking advantage of the flexibility of the nickel.

4x nickels strips welded then folded and welded again, then soldered the end to bind them all together so I could solder my ground connection. This forum page keeps crashing and im tired of it… pics will describe last steps, ask questions before taking on a project like this, building packs is walking a razors edge but precautions will lessen the chance of injury.

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Both positives were left long till i knew how to handle the heavy packs together safely, again decided to weld for strength and a lower profile.

Added fours screws to trampas design to increase the strength in the corners where it is weakest.

Loop key

Final setup with bluetooth and ppm dongle.

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These Molicel’s are way too good for us, I’m so glad they exist. I doubt they’re going to run 45 amps for long so I approve of the 4p.

Post pictures, I’ll be watching.

They really are. When I heard we had a 45a cell over 4000mAh i knew what my next pack would be comprised of! Lordy knows what we will have next!