Capasitor, i sen and smelled too many lipo batteries go up in smoke in regard to RC "toys"
And some cheap cameras is proberly not made with fireproof plastic, meaning if it go wrong whn you are not there your car will burn down to the ground.
I am willing to use my lipo USB power bank, but only cuz its in a all alu housing, so any lipo fire should be contained within.
This is offcourse a larger than a dashcam battery, but you catch the drift.