There are several aspects of a battery jump starter. You have to check how easy it is to start a car using this device. Check the power of its battery and the system. It should work even in tough conditions. Look for a compact and portable setup that is easy to carry. Most importantly, it must be effective in jump-starting the model of vehicle you have.
Some jump starters have additional features and functions that are not necessary but prove helpful. You have to pay more if you buy a starter with extra features. Do not compromise on safety. The setup should be safe to use during both operation and storage. Will you be using it to start a car or some other vehicle? The device to start a car is different than the one needed for more heavy-duty vehicles. It should be able to start your vehicle quickly and properly.