I'm old school when it comes to these, and my use case wasn't exactly for boosting to start. I know it's 2026, but I'm still skeptical (more with performance than safety) of all variants of Lithium batteries, and have had mixed results with them spanning various applications.
I bought a JNC660 (Jump and Carry) a few years ago that I used to provide an extra level of confidence when doing ECU programming as its primary use. I believe these sit on the market right now around the higher $200 end of that price range. It has come in handy for several other jump starts and 12v testing purposes as well. A bit on the large and heavy side (due to the SLA battery in it) though for something to be kept in vehicle for emergency boosting though, I also can't comment on how it holds up being stored in a cold vehicle as mine has always been kept inside the shop or house for when we need to use it. I still stay boosting from another running vehicle (of the same system voltage) is always the most reliable, but understand those situations when your stranded alone.
