The problem with these portable jump starters is that they are notoriously unreliable. They usually are at least a year old (battery wise, The battery has been doing nothing for a year, not good) before they get on the store shelves, the jell cell batteries in them don’t like to be overcharged, the things generally don’t have a great charge controller in them so when you plug it in and leave it the battery gets too much voltage and the battery while showing a full charge doesn’t last very long.

I worked for a guy that owned a used car lot and had a lot of these things laying around that were not that old. It’s less expensive to just buy another jump box then it is to replace the battery in it.

If you are going to have a portable reserve battery, you should invest in a good adjustable charge controller and figure out the voltage charge limits for the type of battery you are using. Most people think this is not needed and just plug the battery into any available power source and call it good.


Portable battery power is about more then a battery, it’s a reserve system. The battery is only one part of that system. The charge controller is just about as important as the battery if you want it to work for a long time.