I bought this unit about 2 years ago and it has worked great. Some people have issues with using the jump start but mostly this is due to not following the instructions in the manual. To jump start the unit charges a capacitor. When you attach it to you battery you have about 30 sec to attempt a turn-over. Then you have to wait for the capacitor to charge before attempting another turn-over. I have used this unit to jump start the car and when my battery went completely dead I was able to plug it into the lighter so it could back feed power to the system to keep the car running while I drove to a repair shop. I had power go out while moving into our new home four years ago and used my father's unit to power two lamps and a radio for the painters. Which is what lead me to buy one. I have also used it camping. Recently I did break off the compressor hose nozzle, bummer so I will be purchasing another unit.
this unit is awsome!...it holds a charge for weeks,and the power on this is more than enough to do what you need to do in an emergency or for casual use. we ran our kids movie player and our laptop in the car for a six hour trip.