√ Weld a new core to the old BMS. No more non-genuine message.

√ Use a Tag-on Flex to change the data and the battery health shows 100%.

√ Old BMS supports future iOS update. 

Disadvantages

New core and old BMS and Tag-on Flex.

Professional spot welding required.

Old data in BMS, Tag-on pretends data to be new.

The old BMS cannot fully utilize the new battery core.

Risk of problems caused by inaccurate measureme