3 years ago, I published an Instructables where I demonstrated a way to jump start a car using a battery from a drill.
Some people were not sure if it will work on bigger cars as the car I used at the time was Kia Picanto.
In this improved Instructable, we'll jump start 2009 Opel Zafira, 2L Diesel and discuss the best practices.
You'll need a fully charged battery from a drill or other power tool.
It's important that the battery is indeed fully charged. A half charged battery might not give you enough power.
I used 14.4v battery.
Batteries between 12v - 18v should work just fine. Some people even reported using 20v batteries with great success, but I wold not go that high.
Depending on the battery you use, you'll need to get creative.
I connected small alligator clips to extend battery terminals. I put a sponge between the clips to avoid accidental s/c.
First you'll want to connect the positive (+) clip to the dead battery, then the other end to the drill's battery.
Then I connected the negative (-) clip to the drill's battery and the other end of the cable to unpainted metal part of the car. In my case it was a bolt.
Wait between 5 - 10 minutes before trying to start the car.
If you're lucky, you'll be able to drive away.
I did a few experiments and found out that the battery could only start the car once. If I stopped the engine and tried to jump start the car again, It was not possible - you would need to charge drill's battery again.
That's why it's a good idea to let battery charge for a few minutes before trying to start the car.
Is it safe?
Nothing is 100% safe.
I would only use this method to start the car if there is no other way to do it.
It's unlikely that you'll damage your car or the car's battery by doing this.
Cars are made to be abused. They have a voltage regulator that prevents overcharging and protects electrical system from the damage.
If something would fail, most likely it would be drill's battery....but it's unlikely...unless you use it for jump starting cars all the time.
Use this information at your own risk. As I said before, this method of starting a car should not be a danger to your car or to yourself, but different batteries act differently. There is always an element of danger present.