Monthly Archives: July 2025

By   July 16, 2025

Still procrastinating on sheet metal.  Also procrastinating on taking apart the back half of the transmission to work on an adapter plate.  Also procrastinating on removing the drive train from the chassis to see whether one of these battery packs can be made to fit.

I’ve been working on trying to talk to the BMS in one of the battery packs.   Turns out each of the battery packs had drained down quite a long ways and since I don’t have a 350v power supply, I decided to charge the modules individually at very low current.  The good news is the battery modules charge up to at least 42v (12s; I haven’t tried to go higher than 42v) and hold their charge for a week at least.   Planning to do some load testing soon.

In the meantime, I’ve been trying to strike up a conversation with the BMS in each pack using this firmware.

 

My Saleae Logic analyzer is seeing the correct packets but the Lilygo CAN interface is not seeing any CAN packets.  I think I’ve fried the transceivers maybe.  Another board is on order.   I’m pretty sure this is the case because it can’t see any CAN packets even from other CAN devices that are known working.

(id: 0x112 is a valid BMW SME status message).

By   July 1, 2025

I’m procrastinating on rebuilding the rear quarters.   I’ve got 6 separate and not perfectly shaped pieces I’m trying to put together so I’m in avoidance mode.   Found some battery packs at auction.  42kwh packs from a 2021 BMW i3.

 

Also got around to getting the transmission spinning using a 33v33A bench supply as well as a 12v3A bench supply for the controller.

Click to watch a motor spin.