Inmotion wheels cell balancing - BMS

[lagger]

Hello, there are some rumors about V8/V8F/V8S not having balancing, also heard something about V10 not having it. That looks not plausible to me for V10. About V8 I heard some cases where the range dropped significantly and it was found the cells were not in balance. Mr Wrong Way warns people about it in his videos.

So I would be glad if someone could solve this mystery. Is there someone who had teardown their V8 pack and inspected the BMS?

[Chriull]

2 hours ago, lagger said:

So I would be glad if someone could solve this mystery. Is there someone who had teardown their V8 pack and inspected the BMS?

It seems it was just a misunderstanding between adam and/or ecodrift and the inmotion technician/contacts.

and the following post.

2 hours ago, lagger said:

About V8 I heard some cases where the range dropped significantly and it was found the cells were not in balance.

The 480Wh 84V V8 has a 20s2p config with ~3.5Ah 18650 li ion cells.

This 2p configuration easily (over)burdens the li ion cells during "motivated" riding. Especially at low battery charges.

So cell deterioration and unbalanced cells can happen - beyond the possibilities of passive cell balancing.

 

[lagger]

Thanks for reply, its really confusing. I have seen a few videos like:

You can clearly see some IC with resistor array. For the confusion to stop, all is needed is someone who check the model of the IC (where cell groups traces are connected) and look for a datasheetof it. From the videos its very hard to say.
 

Edited July 12, 2022 by lagger

[Chriull]

13 minutes ago, lagger said:

From the videos its very hard to say.

On the photo from ecodrift it's easier to see: 

 

13 minutes ago, lagger said:

, all is needed is someone who check the model of the IC (where cell groups traces are connected) and look for a datasheetof it

Unfortionately the labels cannot be read on the foto, but such a conglometarion of resistors on a bms pcb can reasonably be only for passive balancing.