How well do "compact jump starters" work ?

[Stephen Tashiro]

Nowdays there are very small gizmos sold as "compact jump starters" for cars. To what extent do they work ? How many tries do you get at cranking the car ?

Some of them (like "Bolt Power D28A") even advertise the additional feature of being a compact air compressor !

[Kev Williams]

A friend of mine gave me a Red Fuel L-iron jump starter for xmas a couple of years ago. It's about as big as a big I-phone, but about an inch thick. Fits in any of my gloveboxes, but it works! You MUST keep it charged good though.

I also have a Stanley jumper pack the wife gave me last xmas, more the actual 'battery sized' units. It's successfully started 2 cars with low batteries since I got it, and it has an air compressor that aired up 4 low tires on a boat trailer. Took forever, but it did it, without running itself dead doing it...