Chi CBCSO firmware settings and BMS configuration

Some of the pre configured voltage settings on the built-in BMS could cause the the board to power off while braking near full charge. To help prevent this the cell high protect values need to be slightly increased. We will use the high voltage tilt back setting in the controller config as our warning to stop vs the board just turning off. We will also set some amp limits within the controller settings to prevent overdrawing the BMS.

Open the VESCTool and set the following:

APP CFG > Balance > Tiltback > High Voltage Tiltback: Set the “High Voltage” value to 85v (4.25V per cell), the “Angle” to 5…8 deg, and the “Speed” to 1.0/s - you don’t want fast tiltback on downhills or while braking!!!.Also the angle should be high enough to be noticeable but not crazy high - again, keep thinking of those downhills

APP CFG > Balance > Tiltback > Low Voltage Tiltback: Set the “Low Voltage” value to 60v (3.0V per cell), the “Angle” to 10 deg, and the “Speed” to 2.0/s (also, keep it fairly slow).

MOTOR CFG > General > Current > Battery: Set “Battery Current Max” to 35 A, and “Battery Current Max Regen” to -35 A.

MOTOR CFG > General > Voltage: Set “Battery Voltage cutoff Start” to 54 V, and “Battery Voltage Cutoff End” to 50 V.

Next we need to configure the BMS.
Plug your board into the charger to make the BMS discoverable.
Use the Smart BMS app to connect to the BMS over Bluetooth.
Go to Parameter Settings in the bottom right.
Change cell volt high protect to 4.35v and press Set.
Enter 123456 for the password when prompted.
Next change sum volt high protect to 87v and press Set.

No other changes are needed in the Smart BMS app.
*Do not enable the balancing switch in the Smart BMS app. The pack will balance as needed with the existing configuration.

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FYI, Chi had suggested setting sum volt low protect @ 58V (vs 54V here)

That just further shows their shocking lack of understanding of how a BMS should operate and what the operating range of the LiIon cells they use is… Ignore them.

Hey Phillip, thanks for sharing, super helpful! Sadly my bms module is not working, Chi is sending a replacement module.

Could you share what were the stock bms settings please?

Rated capacity is set for 30 ah. Should I change it to 5.6?

I would say yes. Anything other than 5.6 would make the soc incorrect

Fun fact: Daly has an instructional video on how to configure their BMS via Bluetooth - in it they set the capacity to 30Ah… did Chi just blindly follow that video??

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Man that would be pretty pathetic if that’s the case
:sweat_smile:

I currently can’t connect to my BMS for some reason. When I plug my vesc into the wall socket the BMS Bluetooth does not turn on. During installation I was able to hit the button and connect with the app. Weird.

I have hit up chi to see what they say.

In the mean time I can’t make changes to the min and max voltage and the rated capacity. What happens if I don’t set the capacity to 5.6? Should I not be using the battery at all?