Battery/batteryless Jump Starter

I’ve had one of these Li-Ion battery jump starters for a few years and it works very well.

I’ve never had to jump my vehicle, but have used it on several others. It can also power a notebook PC or charge your cell phone. The only disadvantage is remembering to bring it in and recharge it once in a while.

There are jump starters available that have no battery, but use a super capacitor with a booster circuit. It can be hooked to a low battery, but not completely dead, and charge itself to a higher voltage and so be able to start the vehicle.

Here’s one:

The advantage would be that you don’t need to keep it charged, but on the other hand you can’t charge your phone etc.

Anyone have experience with one of these? Good or bad?

Consider me uneducated as far as electronic circuitry goes.
I thought a supercapacitor was basically a battery.


I really like those Li-Ion battery jumpers. VERY HANDY.

But I digress. My understanding is that a capacitor can discharge very quickly. A different type of battery. My wonder is this… This capacitor charges from a low battery that can’t start the car. …OK. And then somehow the shock of a fast discharge from the capacitor BACK to the battery is gonna feed enough power to turn over the engine.

Color me skeptical. No free lunch etc. But I am curious.

It’s not back to the battery. The current flows to the starter.

The idea is that you collect energy over a longish time (several minutes?) which is then delivered over a very short time (a few seconds) to the starter.

I might be mistaken, but I thought they had a boost circuit to take the voltage available and boost it to 12 or 13. The device does stay connected to the cars battery while it’s starting. Several of my led flashlights have a similar circuit so the light stays bright until the battery is nearly discharged.