[Flasher]

my BMW i8 hv battery sits around 79% remaining capacity, still useable but the electric range is very poor and i am considering upgrading the 20Ah cell packs to the newer 34 Ah packs.
the SME programming and the CSC communication structure were changed in the updated version but my estimated guess is i can change the bare cell packs to the 34Ah versions as long as i keep the original electronics .
the electronics will not see any difference except for the longer time it takes to charge and discharge the cell packs - the only electronic part in the cell blocks are the NTC's and i see no reason why they would change their values so after charging and changing the cell packs, renewing all gaskets ,making sure the equipotential screws are fitted correctly and refilling the refrigerant there should be no need for an EOS test to get it up and running - the voltages of the packs are the same , just the weight is a bit heigher and charging takes some more time but to my opinion it should work without any problems after refitting the upgraded HV battery .....
The car will never know the HV battery was removed as all electronics remains the same - i only have to write down and keep the cell pack serial numbers for comparison of the old / new cell pack locations.
I have to do some more investigation but i consider to use the 6 pcs 34Ah cell packs from a used recent BMW 530E SP41 HV battery - it would not make sense to use different cell packs for all different models because a modular setup is much cheaper for BMW .....
I would like to hear your opinion and comments about my idea - i will do some more investigation but at some point i will take the risk because this would be a relatively cheap option to upgrade my BMW i8 to the LCI level....

EDIT - i did some more research and discovered that the pre-LCI BMW i8 ( with 20Ah cell modules) has two CSC modules per cell module (total 12 x master) with two connectors with each 15 connections (total 30 connections) to the cell packs- they also have a total of 6 NTC's per cell pack ( 2x cell 1 , 1x cell 6, 1x cell 9 and 2x cell 16 of which the double + and - ntc's are probably only used for redundancy when one of the others fail...)
the i8 LCI version ( with 34 Ah cell modules) has only 6 CSC modules of which only one is the master and the other 5 are slaves and has only one connector with 24 connections to the cell packs.

the newer 740E / 330E models ( with 34Ah cells ) have the same setup as the newer i8 LCI version but they have 27 connections going to the cell packs instead of 24 (LCI i8) - so i will have to figure out how to connect the two old CSC modules of my pre-LCI i8 to the newer cell packs ( total of 30 connections old to 27 connections new).
As the setup op the cell packs is still the same ( 16 cells in series and 3 ntc's per cell pack ) this should be doable but requires good concentration, no mistakes allowed !

Any thoughts or comments , please post as i don't want to overlook critical things - thank you !