Currently, I’m physically on my second electric longboard, electrically I would say it’s more like my 4th electric longboard. Last summer, I replaced my LiPo cells in a 6S4P (6 in series & 4 in parallel) configuration that was surrounded in by a sheet metal frame with an 8S4P 18650 cell setup surrounded by a custom 3D-printed enclosure in ABS. This gave me a much lighter and thinner board which was great for carrying the board and also gave me additional speed (at top speed of around 20-25 MPH or so) at a range of about 25 miles. In order to do this, I moved away from using a balancing charger and started using a Battery Management System (BMS) board. You can find these very inexpensively on eBay or AliExpress and they mostly work as advertised, but you do get what you pay for.
Anyway, this summer I discovered that in 4 of my battery modules, which is all of them, I had at least 1 dead cell. Not ideal. The one thing I noticed that was common in all of them was the placement of the damaged cell. They were all directly beneath the BMS board. The BMS board balances cells by resistively discharging them and converts this electrical potential energy into heat. I don’t think it was a coincidence that this massive heat generator’s location and the bad cells’ locations was a coincidence. The BMS, if it generates a lot of heat, should not be adjacent to any cell.
So, currently the battery modules are in an disassembled state as I work on my own custom BMS solution.
First, I have to get my BMS system up and running. That way I can reassemble the battery backs and have a reliable way to keep data on the packs and keep them healthier. I’m also working on an accompanying board to the BMS boards that will supply the board with further statistics. It will also be a receiver for a controller and I hope to have a controller which displays important information about the board such as speed and miles (or kilometres!) remaining. Let’s make a Tesla of smaller electric vehicles, it’d be fun.
Not much, unfortunately. I’ve been pretty stuck on the project since 2018 when I encountered my first major mechanical challenges.
A lot! I am going to add my BMS modules to this project’s modules as well, create a bike management board which aggregates data and provides useful user data similar to the electric longboard, but also manages more lights and features. I still need to figure out a proper drivetrain for the bike. I think I will be going the hub motor route due to simplicity, but a ratcheting pedal setup with a mid-drive motor would be, in my mind, ideal. Stay tuned. If I move to California, I hope for this to be my main source of transportation. 1.2kWh of battery and TBD levels of output power :)
This project, similar to Shazam, basically fingerprints music, adds it to a database, and allows for song identification by referencing said database. You can check out the Github Repo here!
Again, not much, but Connor, Hayden, and I are working on a new general management system for our college radio WJRH (104.9 MHz) which we will hopefully use this project in. It would be great to get this project in a production environment.
A good amount. I finished the CUDA side of the development back in 2018 to a point where I was happy but there is still a pretty big bug list which you can find here: Bug List. In addition, I need to get this package into a convenient Docker container for AWS and an API so it can function more like a service (I heard micro services are the new THING).
I have a bunch more projects in my Ideas Trello board and some, such as the BMS, that are really moving along and they will have their own dedicated posts soon. But to those you saw my previous blog, hopefully this post will help make clear what’s been up recently!
See you all again soon!