Inokim Light 2 electrical repairs

After disassembling my Inokim Light for a spring-clean-up I’ve found out that it has severe water damage inside, after running on wet roads all autumn, and getting submerged once in a deep puddle.
It looks like, because of the shape of the frame, front lid placement and the synthetic sponge used to secure the battery, water pooled on the bottom of the unit and remained there for a long time.
Also, no care was given for connector protection.

The battery connector crumbled in my hand as I tried pulling it out – this might explain why I was seeing a quick battery level drop: the increased connector resistance.

This was the only damaged connector, as it was placed on the bottom of the frame, and electricity + water did their magic on it.
After seeing this I’ve also disassembled the battery, fearing even worse damage inside. Luckily the battery was kept above the bottom of the frame by the foam pads and the ones that assembled it did a good job: the cells are placed in a box made of FR4 sheets, with some foam pieces as spacers, everything was heat-shrunk and some silicone was used on the ends.
Also, dismantling the battery made the connector replacement safe because I could disconnect the output cable from the battery terminals

After reading about waterproofing, I’ve discovered “butyl tape” that’s used on ships, cars, etc. That stuff can stick to Teflon.
I’ve decided to get a new set of XT60 connector, some large heat-shrink tube, a roll of butyl tape and try to re-build the battery

The fix had to start with a fix: the rubber spacers inside my hot air station perished and broke apart -> the air pump was jumping all over the case and made a horrible noise. The wires and hoses where long enough to allow me to pull it from the case and keep it on the side, so it would not rattle.

The plan was to use heat-shrink tube over butyl tape, so it would be compressed and pushed inside all spaces.

I did not have the proper diameter tube, so the result is ugly. I think there is enough tape inside to keep the water away. I’ll trim the empty end so it does not become a water reservoir

The next step was to re-build the FR4 battery cage. It’s held together with Kapton tape strips. I’ve added some tape on the edges of the cable output plate, as it had sharp edges and I was afraid it would cut the wires.

You can see the re-soldered wire that I disconnected during the connector replacement

After that I’ve cut a piece of heat-shrink tube and started re-building the outside of the battery. I had the bad idea to use some butyl tape on the FR4 strips. The tube stuck to it and I wasted 30 minutes cleaning everything out. It was my first time using large diameter tube, so I made a lot of mistakes: I did not leave enough extra material and did not cover all sharp corners. The result was not great, but it did the job

The last step was to seal the battery ends. For that I used butyl tape and the covered everything with a layer of kapton

rear end, tape layers still visible
front end, some of the tape was spiraled on the cables, to seal that area as well
bottom end, after applying kaptop tape

The power controller connector and box received the same treatment after replacement / clean-up.

Category: e-PushBike
Comments are disabled