I have the product you linked in the trunk of my car. So far I've had to use it twice and, just like you, it worked beautifully each time. I wouldn't recommend

I have the product you linked in the trunk of my car. So far I've had to use it twice and, just like you, it worked beautifully each time. I wouldn't recommend it for your cell phone but it's way more convenient an emergency kit than jumper cables.