bottle battery 36V 9Ah for standard bicycle bottle holder

thingiverse

This is my attempt to create a sleeper e-bike with a bottle-like battery design. I used the Keyde motor from Alibaba in the rear hub, which has an integrated controller for very light and simple wiring. The batteries need high current, like HG2 or VTC6, as the motor's maximum current is 13A at 36V. You can try using some 3500mAh with high current, but I wanted a higher power reserve. The battery configuration is 10S3P, and I tried to explain it clearly in my drawing. Connecting each floor separately and then soldering (later spot welding) them together was the first step. The floors may sit on top of each other without insulation since they are always in series, so no problem. Next, I connected the green wires to wire all 10s in series. Be very careful when stacking the floors, watch the rotation, and mark visibly the series number on the cells. Then, connect the BMS wires again, carefully checking polarity, voltage, and working slowly as it can be quite stressing. Prepare for worst-case scenarios, like fires, since the batteries are capable of 60-90A, and the balance lead can glow instantly if wired incorrectly. Cover hot parts with tape. Next, I used hot glue to fix the flowing balance cables, then put some textile tape on the bottom of the pack to give it a softer contact with the bottle. Now is the time to insert into the tube. I highly recommend making a strong string loop around the two middle batteries from the bottom through the two openings all the way to the top. This will help pull the entire stack out if needed. When you try to pull on the wires, it will disassemble between the floors and it is painful to repair. So, you want to have something to pull from the bottom – hence the string. When installed, connect + and - wires to BMS and XT60, then cover all visible contacts with textile tape again. The lock for the top is not very strong, so I use tape around it. The spacers in the picture are from the first iterations; they're ugly and not convincing. I will add the code for tiny85 later, but you have to adjust a little for your needs to measure correctly. Battery electronics consist of a battery level indicator (optional), Arduino tiny85, 8 RGB LED circle, and BMS from Aliexpress with integrated balancer. BMS: https://www.aliexpress.com/item/4000298032624.html?spm=a2g0s.9042311.0.0.7bd24c4dzH62Wa RGB LED: https://www.aliexpress.com/item/32787336145.html?spm=a2g0s.9042311.0.0.27424c4dikZsk4 Tiny85: https://www.aliexpress.com/item/32891293434.html?spm=a2g0s.9042311.0.0.27424c4dqdNHwD Battery used Liitokala HG2: https://www.aliexpress.com/item/4000794648060.html?spm=a2g0s.9042311.0.0.27424c4dlW648v