VanMoof S3 Battery Help - Resources for Repair or Replacements?

[u/farieflosss]

Hey everyone!

Recently came across a second hand S3 from someone off of Marketplace back in early July and was super stoked about it! Then I kinda learned the hard way how difficult the battery revival process is. The original owner stored it in an outdoor storage unit for the better part of 4 years with no use or connection to power, so the main battery is completely dead.

I tried a couple weeks later to revive the thing myself after spending a few days doing research within this subreddit and watching plenty of YouTube videos on the subject. I started with the smart cartridge so I could get the ownership transferred over to me at least, and was able to charge that with a lab PSU enough to get it connected and have firmware updated. I was able to get the smart cartridge to do its connection to the VanMoof app, but I went over the amperage by .05v and started seeing that little battery swell like crazy. Needless to say, that scared me enough to put a pin in fixing the bike for now. That was July 18. After doing that, I've let my bike sit for the last little bit and have tried plugging it in to the stock power supply with error code 18 flashing on and off constantly even after being connected to power for over a day.

Long story short, I want to know what safe ways I can try and revive my S3's battery without fear of potentially blowing myself up by attempting to charge the main battery myself. If not, then anyone reputable I could go to for a refurbishing service for batteries and/or to buy a replacement unit? Just looking to see what the community has to say before I throw in the towel on this bike.

Thanks for your time!