BYD Tang/Seal 12v battery BMS

New-Acanthisitta-721 | 2025-10-09 11:09 | 6 views

For the BYD tang/seal having a 12v battery with an integrated BMS and the negative terminal of this battery is chassis-grounded, does the BMS PCB within the battery pack share this common ground? Specifically would the BMS unit still receive the operating power if the battery’s main negative terminal was not connected to the vehicle’s chassis ground?

Comments (3)

LammersTim 2025-10-09 22:51

Very technical question that may not be answerable until tried out by someone. Theoretically, the 12v and the battery pack have very different use cases. So, taking out the 12v battery would most likely take out services/systems required by the car to operate, rendering it useless until fixed. Just my assumption. Please try it out and let us know. 😬😬

Nos_4r2 2025-10-10 01:10

are you talking about the BMS of the traction battery? Thats an 800v battery system and would not be grounded to the chassis. Everything running 800v power is isolated.

Bear0205 2025-10-10 21:26

The BMS inside the 12v battery is usually referred as LV power management of I remembered correctly, that stays awake with the 12v battery even the traction battery's main contactor is disconnected.

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