ive waited a long time to Sue this as a jump starter, until now it was used as a power bank but only last week my battery gave up whilst at work, just clip this on and it works. One thing worth noting is it needs be 3/4 charged to be most effective jump starting. It’s a good size and fits well in the glove compartment. Charging it overnight leaves a full charge in the morning and when not used it lasts months in the car without losing much power. Potential life saver