Found a product on Amazon: TalentCell 12V 6Ah LiFePO4
It comes with a household wall charger that outputs 14.4v @ 1.5a to charge the plugs into the female tail whip of battery, well I'm curious if I cut and splice the charging input end of the battery to a fuse tap instead of using the wall charger in my car will it still work to charge it safely? wondering if this would be a much cheaper alternative to dedicated dashcam battery packs. thanks
Welcome to DCT @ducdude
It is not a good idea to charge your battery directly from the car's electrical system.
Alternators (especially modern smart alternators) don't always provide the 14.2V-14.6V needed to fully charge the battery, and most importantly the charging current is not regulated and most likely will exceed the 5A max limit for your battery!
For the LiFePO4 battery you need specialized DC-DC charger or DC-DC buck/boost converter with adjustable constant current/constant voltage ( CC/CV ) output.
The cheapest DC-DC charger I could find that will work for your battery is this one (preferred option):
This DC-to-DC charger is designed to fully charge your 12V LiFePO4 batteries from your vehicles 12V system. Providing up to 14.5VDC, with an adjustable 2A/4A/8A output (CC/CV charge profile for LiFePO4). Accepts 8-36VDC input from your vehicle's alternator, or other DC sources.