Replacing the single cells in the battery pack?

[Markinson]

This confirms to me that BMS reads only voltages from individual cells directly.
Doesn’t matter what capacity they have and if they differ slightly or massively.
Which means that we can put higher capacity cells as long as they respect 3.3V-4.1V range which is BMS programmed to monitor. Problem lies in fact that the weaker ones dictate the BMS, not the stronger ones. One week one can cripple the whole system, like in my case and Dondahska’s.
I could find somewhere 96 cells of any make and completely swap them all as long as we connect each cable to measure voltages and temperature readings and security switches. They need to be sized enough to fit into the shell of the whole pack and that they can trigger security switches if they get swollen. They can be 200Ah capacity, BMS will let them charge between 3.3V and 4.1V. But higher capacity for same voltage range, longer charging times, longer driving range.

Yes, I think you're right. This is why e-service.hu could do the 250-290km range with newer generations of cells, changed in soul's original battery housing. They said the newer cells would be able to run with wider voltage interval, but our old BMS won't use their higher voltage capability.
If they could reprogram the BMS, even higher range would be possible, nevertheless the valid range could be displayed as predicted possible range.

I'd be happy to replace the week cells in mine, so I could get back some range closer to the original.
This mild winter reduced my range to a predicted 130km, from which I can achieve max.150km with low heating in urban traffic.

Rural road speed and higher heating means the predicted 130km.

It's not bad, but I don't want to charge always to 100% (even though I know only the week cells reach the 4,11V level first, so the good cells are not really near to suffer damage from full charging).

Thank you for the upload and shared experience and knowledge.

 

[IanL]

I would expect the GOM to be very pessimistic, at least initially, as the algorithm would be unaware of the higher capacity. Depending on the design, it might be capable of slowly adapting.

 

[Perez]

Hello. Does anyone know if it is possible to replace the complete battery with BMS, of an original 2016 Soul with a 27kwh battery, and put in its place a used 30kwh battery? I mean if it is necessary to program the BMS, to adapt it to the new car? Thank you

 

[Markinson]

Hello. Does anyone know if it is possible to replace the complete battery with BMS, of an original 2016 Soul with a 27kwh battery, and put in its place a used 30kwh battery? I mean if it is necessary to program the BMS, to adapt it to the new car? Thank you

As far as I know...
... replacing the full battery pack means, that you replace the BMS as well (which is located inside of the battery pack), so you won't need to program anything.

So, yes, cut-paste and Ta-daaa...

 

[JejuSoul]

Correct. The external dimensions of the case and the external connections are identical.
Read this thread for a case study on how to do this swap.

If you are a programmer and have plenty of time to spare then the VMCU in the front of the car could be re-programmed to alter the driving dynamics. The 30kWh pack is heavier so the car's performance is different.
No one has done this and unless you are a race track driver I doubt you would notice the difference.

 

[kojairvs]

I successfully replaced the entire battery from Kia 2015 with a used one from 2018. The car's computer recognized the new battery without any problems because it receives all information from the BMS belonging to the battery and therefore there is no need to update...
I hope that will be in your case as well.

 

[Perez]

Thanks a lot. I'm glad to read that. So it's a very easy change. The doubt I had is if it has some kind of immo block in the bms by vin code. It also strikes me that the OBC charger has a different reference, may it be that the programming is different for batteries from 27 to 30 kwh?, or they simply took advantage of the restiling of 2018 to introduce improvements in the OBC??

Ref. OBC MY2018: 36400-0E245 Mando Q14.1E
Ref. OBC MY2016: 36400-0E240 Mando V11.1D

 

[kojairvs]

Hi Perez,
Unfortunately, I am not familiar with the changes in the charging system between different models.
It is true that my second-hand battery was removed from a car registered in 2018 in GB, but I think it is the 27kW version because it also only has 96 cells and not 100 as it should for 30kW.
In these few attached photos you can see the difference in codes between my original and used battery.
First photo is from the original and second is from replacing one, continues in that order.

 

[kojairvs]

… BMS from 30kW should probably have 4 more voltage measuring connections, one from each 10 cells modules (11 cells now). That is probably why they supply new harness cables when they replaced under warranty 27kW with 30kW battery. As I could see during my “bricolage” there were always one or two pins not used in multiple pin connectors. Which made me realize that they could keep old BMS and just update it to be able to use/recognize 100 cells instead of 96. And to be able to accommodate higher overall voltage,
If you have original BMS made for 100 cells than onboard computer will just use information received, I guess, and carry on. Only possible issue could be updating onboard computer software if there is communication issues between BMS and onboard comp.
Good luck and keep us posted…