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

Covers electric scooter models whether shared or for consumers.
By sunny
Bastholm wrote:
Wed Jul 15, 2020 9:05 am
Just wanna let you guys know that the battery (i´m not a BMS geek or anything) is only working when using the scooter. Took one battery out and tried to use it with my ebike and it cut off power after 5 seconds. All the rental scooters have the same kind of BMS. So if you want to use the battery, you need to solder a new bms on
You do not need a new BMS .Get the -ve from the BMS -ve and positive from 13+Ve you are good to go . a BMS is useful to balance the cells while charging at least most BMS and protect the cells . In tier scooter case BMS doesn't need anykind of
CAN Communication to charge the battery and BMS works as good as it supposed to while charging. You just bypass the BMS while discharging

By sunny
If you are still trying to make it work in Oct of 2020 here is what i have done after reading all the forums and posts online.

Tier ES400 is CAN Controlled. Maybe you already read this somewhere .Here is the news flash battery , motor even the acceleration is CAN controlled. Without the CAN Communication developing knowledge . its impossible to make them work.

First disconnect the main computer GPS box whatever you want to call.

1.Solution for using the onboard battery....

You have basically a dead battey in a locked compartment which you need to crack open. Once you are in,if you still want to use the same battery cut open the battery case carefully , the battey is potted so you can not get the pack out of the metal compartment without cutting it open. Then bypass the BMS by taking negative from BMS and positve from no 13+ve terminal. Keep all the wires connected so you can still use the BMS function for charging the battey. To charge the battey you do not need to communicate with a CAN message. Once you have a battey ready you can connect it back to the charging port.

2. Disconnect the controller
You need a new controller . this is the only thing you need along with a 54v charger.
connect the new controller with the existing motor cables 3 mains 5 hall sensors you can leave the thin white cable away .if your controller has 6 sensor cables go for it. battey connection can be done later . so you have a controller and battery ready.

3. get the cables from the handle 4break cables two on each side can be connected parallel, 3acceleration cables can be directly connected to 3 cables on the controller. getting the handle cables are a bit tricky since you need to take abunch of screws out .

all thats left is connecting the battery to the controller , You have a working scooter.

total investment -30ish euros for the controller from AliExpress . i bought a 1000watts can also go for 500 but 1000 gives me around 28kms but the torque is pretty good.
14 eur for charger

The dashboard won't be working but hey you have a bulky scooter that can literally take you off-road. i know mine does. you can also get an external display for info along with your controller.

i know this is really a dumb way to hack the scooter. but at the end of the day if you have working scooter without anylimitations why not.
bagnare liked this

By doctormord
The BMS microcontroller is a STM32F0 with brought out SWD-Connection. Also the I2C port communicating with the BMS controller (BQ76940) itself is available via pinheader. RX/TX uart is available at test points.

The microcontroller is readout protected but can get reprogrammed via ST-Link. Minimal code is available for Arduino as well.

The only unclear thing is actually the small display.

By MikeSnow
Posts LikeBB
Anyone tried to connect CAN straight to the battery connectors? In that case which holes in the connector did you use? Speed 250 khz?

I don't have the scooter but I would like to check and see the communication from the battery, or maybe the battery doesn't send anything without the other parts?

One more thing, I found this link where they unlock another type of battery that also uses CAN. Might be a long shot but worth testing the same CAN msg and see if it turns on the output.
Zou liked this

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