Speaking from a person who's worked on electric vehicles -- they can be quite the handful to work on, and incredibly dangerous if you don't follow the service manual to the letter. The current electric vehicles have a LOT of current and amperage flowing thru them, the voltages are higher, etc; one mistake and it's game over. Not to mention, replacing a battery pack or battery cells is not all that easy; it's very time consuming and takes special equipment to do the job properly. A GRX-5100 used to balance current and voltage in the cells of a battery pack after replacing a battery or replacing cells in a battery, that one piece of equipment starts at around $12k. Then you need lift tables to remove the battery from the car, install it back into the vehicle, etc.