75kwh battery specifications vs 90kwh battery... possible to add modules?

[Proxlamus]

Hey everyone I've tried searching around a lot and haven't really found a solid answer.

My interest is to see whether or not I can add additional modules to my 75kwh battery to make it into a 90kwh capacity.

Hear me out..
I understand there is information on 100kwh battery packs, indicating theres 16 modules vs 14 modules. I also understand Tesla was able to pack more cells inside the same amount of space and modifying the cooling jackets to fit more cells.

Looking at the battery (see attached picture) there are additional modules stored in the hump of the battery. Since I dont know the difference is the battery pictured a 90kwh battery? If I have a 75kw battery do I have modules stored in the hump? If not, could I add them increasing the capacity of my 75kw battery ?

I understand it's a rather monumental task to remove the battery, loosen the million screws and break the weather stripping loose and pump all the coolant out and back in, but it is something I'm considering. I tinker around with too many other cars.

 

[Krash]

I had brought this up a few times and Jason Hughes convinced me that I would never be able to match the battery cells closely enough to keep the pack from self destructing.

Yet both the higher range and 400v charging are appealing.

I am resigned to swap my 75 for a salvage 100 and leave the salvage car with my 75.

if you decide to try anyway I would be interested in helping. Getting individual cell voltages from the diagnostic port is easy enough. And I think most module sellers would hookup a voltmeter and tell you how close they are.

Do you know if you have to root your car to modify the battery management system or something in the pack? I have always assumed that if you lifted a 100 battery into a 75 that it would just work, since the 75D w 85kWh BTX8 battery is 400v, but maybe that is naive. In your case of "making" a 350v into a 400v, does the master BMS just count up 25v BMS slave units to see if it has 14 or 16 units? What would it do if it counted 15? Or 13?

More on Hughes' BMS project and a subsequent one.

 

[jaguar36]

Would be a lot easier to just get a whole 90 pack, swap packs and resell the old one rather than try and add new modules to the old pack.

 

[bob_p]

Model S/X have an unlimited mile 8 year warranty on the battery pack and motor.

Making any changes to the battery pack would clearly invalidate that warranty.

It seems likely we'll eventually see a battery upgrade program. With the simpler design, a Tesla S/3/X could have a much longer lifetime than an ICE (Tesloop seems to think they could get up to 1,000,000 miles on a Model S).

But with battery degradation relatively low on the Tesla battery packs, there hasn't been much need for Tesla to implement a battery replacement plan (something they originally considered after the Model S went into production).

This might be an area for Tesla to explore when they see more EV competitors - could be another differentiator, in addition to the Supercharger network - and having FSD hardware in every car built since late 2016.