The BMW i3 is a great little electric car, albeit short on range by modern standards. It went on sale way back in 2013, when it was available with a rather small 18.2-kilowatt-hour battery pack.
That model, labeled as the “60” because of the 60 amp-hours capacity, had an EPA-rated range of just 81 miles. It was later upgraded with a 94 Ah battery that bumped the estimated range to 114 miles. It ultimately received a 120 Ah battery that gave the quirky EV an EPA range of 153 miles.
That’s a significant upgrade, but owners of the original i3 have been left with a rather subpar power source. That, coupled with the inescapable fact that batteries degrade over time, means the older i3s with the 60 Ah pack may now struggle to crack 70 miles on a full charge. That’s fine around town, but taking even a small drive elsewhere is an adventure to say the least.
…
The CATL pack can allegedly deliver a driving range of 248 miles on a full charge. That said, in a video published by MTG, an i3 fitted with its upgraded pack went 186 miles straight on the highway, maintaining 62 miles per hour. When it comes to charging, the new pack will behave the same as the old one, meaning it can accept up to 50 kW from a DC fast charger.
https://insideevs.com/news/756933/bmw-i3-catl-battery-pack-upgrade/
This article says the new battery will run you $5,800 but I have seen them priced in $3,000-$4,000 range. In 3 year you will be able to buy battery with twice the power density for for 1/2 the price.