Yesterday, Jump started the car 3 times with this, After the battery finally failed after 5 years and 10 months, as the starting had become progressively more suspect. Bought a replacement battery. I picked up a couple, after reading up on the Wirecutter, after "someone" managed to flatten a battery by means unknown (probably by leaving a light on, or door/trunk open). Small enough and light weight enough to keep in the car, and get to the battery, if say you have parked nose in, or would otherwise be unable to get a conventional jump start from another vehicle. Handy logic indicator lights in the cable (reminds you disconnect after starting) I'm a believer. Available from Costco https://m.costco.com/Lithium-Jump-Starter-And-Portable-Power-Bank-.product.100312116.html More details from the manufacturer http://winplus.com/usa/products/car-jump-start-portable-power-bank/