Comment by hbarka

> three big bolts under the passenger seats that I have no interest spending my Saturday removing.

I’m not familiar with BYD but yes you need some mechanical aptitude to change the 12v battery yourself.

Premature failure of 12V lead-acid batteries remains a persistent complaint among EV owners and is a recurring frustration. Just go to any EV forum. The traction battery will not top it off either when parked for extended periods.

Lithium batteries generally tolerate periods of inactivity better than lead-acid batteries. The OHMMU batteries are also “smart enabled”, see their website.