When someone comes out with a dashcam using a lithium iron phosphate (LiFePO 4) battery good for years of use and heat resistant, then we'll have better technology. Or make the LiPo battery user replaceable.
I lost my first dash cam (DOD) at less than 2 years use because of the internal lithium polymer flat pack battery that failed. This Eborn camera says in the specs it has one too.
I remember when it was new it would run off its internal battery a good 10 minutes playintg back theough its HDMI out. It got to the point to not jave enough charge to close the last file uopn power down. I tried replacing but it was now really not made to be disassembled and replacement battery I bought did something to the charge circuit, not sure but it wouldn't charge through the camera afterward, but would power the camera until its charge dropped off.
From what I gathered about LiPo battery characteristics those are good for about 200 charge-discharge cycles. And we all know they are heat sensitive.