The Trampa / VESC battery systems

Hi Guys, after almost 3 years of R&D we are proud to introduce the latest in battery technology:


So what makes these packs so special ?

The Trampa / VESC Battery Pack Technology doesn’t use spot welding to interconnect the individual cells. The connection is made via a special, 25A fused contact element, designed for pick and place machine assembly. After out initial investment into R&D, tooling for the parts and tape and reel moulds, we are no able to mass produce tailor made packs for electric mobility and alternative applications needing reliable and safe battery packs.

Using this pack allows anyone to purchase cells locally and fit them into a 12S7P cell array . After closing the pack, you have a perfect battery with a perfect battery management system. And if a cell goes bad one day, you can swap out individual cells or p-groups in no time.

If your cells reach their end of life, you can simply buy new cells and recycle the old. So instead of buying a new and expensive pack, you will only need relatively cheap new cells and 15 minutes of time. The initial investment might equal the investment of a pre-made spot welded pack, but as soon as it’s time to replace the cells, the price drop in getting a second pack is dramatic. Spot welded pack can’t be serviced and are pretty much useless the day one cell goes bad! Way too many good cells end in recycling these days, only because they sit next to a bad cell, permanently interconnected via a spot weld - we resolved this issue and offer an environmentally friendly solution, so that the same pack can stay healthy for a way longer period of time.


There is hardly any wiring involved. Everything is PCB based, neat, tidy and clean.


The VESC BMS on this device is the latest in BMS technology . Using the same chipset that is used by the world’s leading electric vehicle manufacturer, this pack features a self monitoring system of automotive grade. Beside that, the system monitors the pack temperature in several locations and allows placement of an additional temperature probe that can be attached directly to a cell in the middle of the pack. Charge and discharge currents are measured and a humidity sensor monitors the humidity inside the enclosure, so that water ingress can be spotted via App. Did I say App? Yes, the pack is connectable to the famous VESC-Tool App . You can not only monitor the pack, but also work on your pack and start and stop balancing, even if you’re not charging at that time. You will also be able to define cut-off voltages, charge current limitations and many more.
The BMS also features CAN-Bus connection and VESC motor controllers can therefore know individual cell voltages, so that a low voltage cutoff can be executed in reference to the lowest cell voltage in the pack, preventing over-discharge of individual P-groups. The BMS features SWD, isolated CAN and USB connectivity. FW updates can be managed via VESC-Tool and the CAN interface. CAN also allows you to couple individual packs to form a bigger battery array (in series, in parallel or both). The CAN Bus is therefore 600V isolated.


  • Individual cell fusing will give you the confidence that each cell in the pack is secured against short circuiting. A faulty cell would be decoupled within seconds and would therefore not cause any further danger.

  • Temperature monitoring in up to 5 locations of the pack.

  • Humidity sensor

  • Self monitoring, automotive grade chipset.

  • App connectivity lets you see what is going on with your pack. Are my cell all healthy and good?

  • Charge port with Mosfet switch allows the BMS to decouple the charger at any time.

  • Easy to service and extract unhealthy cells.

Pack capacity is roughly 1KWh :

Sony VTC 6: 3120mAh x 7 = 21840mAh = 969Wh

Samsung Q30: 3000mAh x 7 = 21000mAh = 932Wh

LG 18650 MJ1: 3500mAh x 7 =24500mAh = 1087Wh

Build time:

Roughly 45 minutes (if it is the first time you assemble one)

Flight legal:

-Extract cells and box in air travel safe 99Wh packs

-Check with Airline prior to flight

Pack Stacking:

These pack can be stacked in series and in parallel, so that bigger packs can be made from individual packs. This allows to create batteries of massive capacity and desired voltage. If you feel you need 12S 14p on your board: YES this is possible.


Very cool!


Took you long enough!

I held some prototype to this a year or so back, felt really well built then and I bet its even better now. :+1:

@trampa is the BMS part of the OS project?


nice stuff :smiley: I’ts always nice to see such good designed solutions

but i got a question: @Trampa Your boxes are not exactly water or even dustproof… Is there any kind of seal that will protect the battery from the environment?

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The BMS on this pack is quite specific to this pack.
The code will be part of the VESC-Tool and the VESC Tool code is OS. So you will be able to design your own BMS that can run on the code base for our upcoming super small stand alone 18s BMS.


First of all it is quite easy to seal the box if you want to do that.
We also get some nice covers soon, and they sling around the box and protect the box from water and dust and dirt. In the end it is easyer to wash the cover and have a clean box.

I will add this: The pack is humidity sensored.


Pretty neat solution

If I understood correctly the part that make the contact with the cell is custom made? And is the cell level fuse part of that or in the PCB?


You can swap the fuse if you blow one. We did some tests on wrong assembly, basically shortening the cells against each other. Fuses go and need to be replaced, sure.


This is a pack stack. Can be wired to be 50, 100, 150 or 300V


this is per cell in the P-group, right?

hopefully the pack can discharge more than 25a :joy:


Per cell and those are slow blow fuses.


What cells are they? OK can see make

Any 18650. We use the VTC 6


These look very good and I’m sure they will be a good safe option for DIY builders. A few questions.

The product description in your website says 20A cell fuses, can you confirm it’s 25A per cell?

What is the maximum charge current these packs support?

It’s there any discharge protection eg fuse on the output?


Any plans for 21700’s? People seem to be moving slowly to them for the cost/wh and crazy discharge rates


15A charging is fine. 25A cell fuse, discharge protection is cell fusing on the pack side. You need to place a fuse in between pack and ESC. We can’t know what fuse rating you really need and fuses should be matched to the system.

And a 21700 pack is in Benjamin’s and my board and will follow soon. We currently test the TESLA Model 3 cells in our boards and they work quite nicely. This is the 21700 version, 1.55Kwh:


Wow…very innovative! Great to see development on better battery packs. Two questions, if you have the time…

  1. What type of fuses are you using? Will your customers need to buy Trampa fuses or you using a standard type of fuse?

  2. The fuses are in the top assembly that screws down? Or are the fuses on the bottom?

This would have been a very fun pack to test!


The fuses are on both PCBs and we will offer them. Not expensive, and we never blew one other than doing a test. If you avoid putting cells the wrong way around, they are good for a life time of the pack.


What would it cost to buy that setup? Is there a discount to get the battery box and a pair of VESC 6s?

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Proprietary fuses. :pensive:
(Edit) I’m wrong…surface mount fuses.

But you are very limited with space so I understand the need to to that. Glad to hear Trampa will be selling additional fuses!

It would be great if a couple of spares were included with the pack so no one has to wait for new fuses to arrive…just in case.