The chip in the 16V Low Voltage batteries that Tesla uses is the NXP MM9Z1_638 which is a fully integrated battery monitoring device, featuring:
- Support of precise current measurement via an external shunt resistor
- Four voltage measurement via an internal calibrated resistor divider or use of an external divider
- An internal temperature sensor, allowing close proximity battery temperature measurements, plus four external temperature sensor inputs
- LIN 2.2 protocol and physical interface and an MSCAN protocol controller for interfacing to automotive buses
https://www.mouser.co.uk/new/nxp-semiconductors/freescale-mm9z1-battery-sensor/
https://www.mouser.co.uk/new/nxp-semiconductors/freescale-mm9z1-battery-sensor/
https://www.screwfix.com/p/silverline-car-light-tester/213FU#product_additional_details_container
