ApacheXMD said:
I'm not too familiar with the ninebot ES4 external battery, but I have played with a couple of ES2/ES4 internal batteries. I tried to run a 36v hub with a generic motor controller with one of the ES2 batteries, and the BMS would cut out on a any significant voltage drain. I think if the BMS doesn't see a signal from the stock segway controller, it will kill power. I ended up re wiring the discharge leads to come straight off the 18650 cells. Charging is still via the BMS.
They're all gone, but I got four of these "segways" for $25 each last year.
https://batteryhookup.com/products/36v-pack-with-bms-20x-2550mah-eve-icr18650-26v-cells-5-1ah-183-6wh-scooter-ebike?variant=31272284553348
Like you, I found one pack could not push 10A without shutting off. Also, my generic chargers would pulse on/off and that would probably damage them. I repackaged them as two 10S-4P packs with a 20A balance BMS on both. The ICR cells are rated for 7.5A, so each pack has 30A max available. My bikes rarely take more than 500W anyway. That's like 13A continuous.
I think these packs are mechanically quite stout, and with a good BMS, I don't worry as much about them blowing up on me. They still could. It's lithium.