First time trying this device on a vehicle with a dead battery from setting unused for too long. It did exactly as intended. The NOCO pack cranked the engine perfectly.

My opinion, this is a nice quality unit, that subs as a great portable power bank and flashlight. It works well and seems to have plenty of current to spin a starter fast. The outer housing feels sturdy and buttons work well. Water resistant silicone covers over all ports. The battery champ cable assembly also feels well made. Certainly a quality product.

In case you want to see one like this apart, look at this from another channel    • Noco GB30 failure autopsy.  

I discovered that first flashing sequence of the LEDs is SOS.
The combo IN/OUT port is USB-C and charges the unit with any good standard 5V USB charger. A 12V high rate car charger is available for these.

NOCO Boost X GBX45 1250A 12V UltraSafe Portable Lithium Jump Starter, Car Battery Booster Pack, USB-C Powerbank Charger, and Jumper Cables for up to 6.5-Liter Gas and 4.0-Liter Diesel Engines https://a.co/d/9bUoo4z