We TRY (operative word) to use these rechargeable jump boxes at the PD where I work to avoid the hassle of using jumper cables.

The problem being that they NEVER have enough battery power to jump even a go-cart. They are a good idea but fail when needed most. They are heavy and prone to being discharged. The only time they have ever worked is instantly after removing them from the charger.

If there is one that recharges from the car's alternator while the vehicle is running, that might be a better option.