Replacement high voltage batteries

I3drivei3 · Nov 27, 2024

I recently purchased a top of the line 2015 i3REX with 60,000 miles in fantastic condition for $12,000. It just had the high voltage batteries replaced under warranty, so the car feels brand new to me. The previous owner had 69% left on the batteries so BMW replaced them. I feel like I got a great deal.
Is the technology in the new battery packs that were installed better than the technology on the original battery packs? It is different at all?

mojo · Nov 27, 2024

I3drivei3 said:
Is the technology in the new battery packs that were installed better than the technology on the original battery packs? It is different at all?

Each of the three variants used (AFAIK) Samsung SDI cells using similar cell chemistry, but three different generations, with improving packing density. The oldest of the three cell generations is widely recognised as being the poorest performer in terms of battery degradation with time/use - though of course any real-world statistics of that will be distorted by the fact that they are older than any of the later generations.

The technology itself did not, as far as I'm aware, change in any fundamental way.

Anecdotally, total replacement of the battery pack under warranty appears to be far more common with the 60Ah packs, and relatively rare for the 120Ah packs - again you have to account for the fact that the latter will on average be 5 or 6 years younger than the former.

EvanstonI3 · Nov 27, 2024

The battery pack was replaced with the same type of batteries, not some updated varient.

jbond1972 · Feb 17, 2025

I3drivei3 said:
I recently purchased a top of the line 2015 i3REX with 60,000 miles in fantastic condition for $12,000. It just had the high voltage batteries replaced under warranty, so the car feels brand new to me. The previous owner had 69% left on the batteries so BMW replaced them. I feel like I got a great deal.
Is the technology in the new battery packs that were installed better than the technology on the original battery packs? It is different at all?

How did you get the battery replace for free the was the battery defective? I have a 2015 BMWi3 Rex also went to BMW to do a test on the battery my result at 67% and I still cannot get a new battery. Please explain how you got your battery replace for free, was the battery defective in any ways. Thank you.

Mondomensch · Feb 17, 2025

jbond1972 said:
How did you get the battery replace for free the was the battery defective? I have a 2015 BMWi3 Rex also went to BMW to do a test on the battery my result at 67% and I still cannot get a new battery. Please explain how you got your battery replace for free, was the battery defective in any ways. Thank you.

What did bmw say when you asked for battery replacement under warranty?

mojo · Feb 18, 2025

If jbond1972 is outside of the US, perhaps BMW have said that the battery warranty has expired? AFAIK, all European cars have an 8-year, limited mileage battery warranty, so at this point in time a 2015 manufactured car would have a battery that is more than 8 years old.