Questions on Original Pint conversions

Got a few questions for anyone that can answer them for me.

I have an Original Pint - the battery is shot, the BMS may or may not be, and I have no idea about the controller (Though I suspect is functional) I bought it used, enjoyed it for a few months before the snow and left it on the charger for it to kill-itself over said winter. Alas its been disassembled for a year or two at this point.

So I know I need a new battery, and if I’m going to go that far since Ill build one of my own, Ill just yeet the BMS, and the Controller while I’m in there. I am no stranger to custom builds in the PEV space (Mountain Boards) but I am finding my self at a loss when it comes to generalized compatibility for the OG OW Pint.


The Ubox, LittleFOCer and CheapFOCer v2 seem like the typical units, though I suspect any VESC-Based ESC with an IMU (with 15s voltage support and a Bluetooth module of some kind) would be reasonable (SKP, FreeDrive/KingFoc/WhateverItsCalledNow, etc). I currently have no idea which I’ll pick at the moment, the Ubox was the plan but it seems the Ubox Lite is OOS and v2 is around the corner. I had planned on doing a run of 10-15 FreeDrive boards as I’ve had considered the idea of converting my existing two Mountain Boards to 4wd.

So here comes a few questions:

  • Am I correct in my assessment that pretty much any VESC-Based controller that meets the criteria (BT, IMU/BMI, 15s+ Support) is sufficient, or are there small “hidden” gotcha’s with different vendor ESCs and how they interact with supporting components (foot pads, momentary switches, lights, etc)?
    • If I am not entirely correct, please share any insights/elaboration.
  • Am I missing or “sleeping on” any other VESC Based Controllers that should be considered?
  • I know way back in the day (when V6 hardware was the new hotness) you could add BMI/IMU’s to controllers via UART (I think) but I suspect that is frowned upon now days. Correct or not really an issue?


Probably the single biggest concern I have is the spacing in the battery compartment. I wanted to grab some 21700’s (P42A, P45B, or 50S) and do a simple 15s1p but I am getting conflicting answers when I try to find any information regarding if the 21700 volume in the 15s1p is too big for the original Pint battery housing. That said I’m not dedicated to 15s, given that I’m going to VESC-Based I could run really anything but I’d like to keep it contained in the battery compartment. So for the sake of the simplicity of my question Im sticking with 15s unless someone has other insights to share.

Furthermore, I plan to remove the existing BMS and use something else - was planning on a daly BMS for charge only since if im going to VESC-Based I can just run a can-enabled Daly into the controller as well. There are other BMS I’ve seen around but Daly seems to have a solid hold on the market for price/features.

I do understand that in this instance I probably will end up having to cut the battery compartment to make things fit (some plastic bits to isolate the Original pack from the BMS (or something to that effect) for the sake of making everything fit thats not a big deal to me.

On to these questions:

  • Will a 15s1p 21700 pack fit in the Original OW Pint battery compartment with or without modifications?
    • If mods are required what specifically?
    • Is there space to increase the size or is that pretty much the limit?
  • Considering the use of a Daly BMS for charge only, will that cause problems for me with respect to compartment clearances? ( I know they come in a variety of shapes and sizes, feel free to give an example if you have one).
  • Considering the general lack of space on these boards (Pints) I would be absolutely surprised if someone hasn’t just split their pack and run some cells on the controller side and some cells on the battery side. Is this still something people do from time to time?
    • Given the questions above regarding pack size, is it worth it?
      • I suspect its better to just do one of those vamp and ride style fender batteries (DIY of course) rather than dealing with securing cells in the controller space but again not entirely sure.

Misc Stuff

Generally speaking if you have any resources for DIY parts, 3d printed parts, guides, documentation, I have tried thoroughly to comb through pevdev, reddit, and anywhere I see Mario interacting for information pertaining to the details I’m looking for above specific to the Pint, or balance boards in general. Any kind of guidance would be massively appreciated.


The LFOC3.1 and Ubox are pretty common and well tested in the pint.
Not sure if you can fit a 21700 15s1p in the box though.
Daly BMSs are good but you probably won’t be able to fit one inside either of the boxes. There isn’t much room. I think the PintX battery box is a little bigger. I keep a Daly on the bench to balance packs outside of the board. There are other BMS options that will fit though.