An Electric Scooter Community on a Mission to Stamp out Transportation Mediocrity.

Store the power! Electric scooter battery and charging discussions go here.
By xecuter77
baubabauu wrote:
Fri Aug 27, 2021 1:56 am
Tried to push cells ouț and this happenedImage

I am waiting for other way to work the battery.
It runs into protection after a few seconds

Hello, did you solve the problem how to extract the Cells?

Thank you.

By Eichelhard
Guten Abend könnte mir irgendjemand für solch einen Akku ein Ladegerät empfehlen. Mfg Chris

google translate from German to English:
Good evening, could anyone recommend a charger for such a battery
By Mobibilis
Hello, about the extraction of cells, I spend many days with threaded roads, 6-8mm, but low speed extraction. It is much easier with small hydraulic piston for cars, very cheap.
By Cologne
STO wrote:
Thu Apr 14, 2022 2:21 am
I have 15pices of the okai es 400b battery

I like to build a powerwall and use the battery s

But I dont like to rip them apart

Is there some communication I need or tldid they stay on all the time?
If you want to use multiple batteries as a powerwall it can get very tricky. The BMS charges without an activation, but you can only decharge it when it is receiving the unlocking message which I am still not able to get. The problem there is that the flow of the activated battery will charge the other batteries. As the voltage decreases in a battery it can even harm the other batteries, when they have a higher voltage than the active one. If you don't want to cut them open you probably have to build a system out of relays which put the inactive batteries off your "grid". I also do not know how the BMS reacts when it is activated and charged at the same time. It could work.. or it's blowing up.

I personally got good results while using a circular saw with a max-height protection. 2 cuts on the side where the BMS is and then just bend the case.

My problem now is to get the 21700 cells. If you manage to get the pack without exploding congrats. But gettings the individual cells, I didn't find a way to get that pack open. Its just very tight

By Cologne
There are 2 versions of the battery pack.


I hide the QR-Code and serial number for tracking reasons. Each battery-pack has a unique number. But reading the serial number and assuming that a lower number means earlier build date the one with more Wh is older. Can anyone confirm that?
By Cologne
I just got 10 new ones of these batteries. Having almost 7kwh of battery got me thinking of stealing someone elses idea and rebuilt them to a DIY Powerwall without opening them up.

First of all I want to get the statistics from the bms to my esp32. In order to do that I could try forever with CAN-Bus or I just sniff the SPI connection between the Board and the Display.


I can't really find anything about a "TMI1621" chip. but there is a TM1621 and other TM16xx similar chips on the market where you even find arduino libraries for. The ones I found to send signals but its more or less nonsense.

First I want to find a way to control the display from the ESP32 to just learn how it works. And it's quite easy by just sending raw bits turning on and off each line or symbol:

Now I will have to figure out how the Touch Sensor communicates with the board and controlling the LED with doesn't seem to difficult :)
By MikeSnow
I'm trying to do the same thing but I can't figure out how the battery communicates since I only have the battery and not the entire scooter.

Have you figured out what kind of protocol the battery uses? I've read that it's using CAN on different forums but after measured the pins I'm not that sure, it doesn´t look like CAN to me.

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