Lithium Ion Battery Jump Starters

[suprf1y]

In an effort to get as light as possible I used to run a Lithium ion battery in one of my previous cars. It was technically a summer only car but I drove it as long as there was no snow or salt on the road. It got pretty dicey in late November/early December after a 12hr night shift. It always started, but since they regain voltage as they heat up, I often had to short crank it 3-4 times to let the battery heat before it would actually turn it fast enough to start.