I had to buy one of these today at Canadian Tire to Jump start my car.
They have them on Amazon.com for $149 and I can tell you that they store a lot of power - enough to start my dead battery in -40 celsius temperatures today - enough to get me to the Dealership to get a New battery.
Mine was dead after 5 years and 5 days 0f -30 celsius arctic vortex winter weather. As usual Dewalt makes a great product. I will be taking this with me on any long winter road trips.
DEWALT DXAEJ14 Jump Starter: 1400 Peak/700 $149 .... http://amzn.to/2BWtVBa
1400 Peak Amp, 700 instant starting amps
120 PSI Digital compressor with auto stop and and a surefit nozzle
Patented Alternator Check function
Two 3.1 Amp USB outlets
Heavy duty powder coated metal clamps and LCD screen