Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Avoid this product

1. The battery booster will not start a car with a dead battery. It only works with a battery that has run down to the point where it will not turn over the engine. You will need a much stronger booster to start a car with a totally dead battery.2. The booster can ruin the computer electronics on some cars. This is stated in the instruction manual. However, when I called the Black and Decker service center, they had no list of which cars would be effected. The service tech said he wished he had a list but he didn't. I guess you're just supposed to try to use this product on your car and find out later.3. I have not returned the product since it will boost phones, etc. and may have some use. However, if I had known that it did not work on dead batteries and could ruin my car, I would never have purchased it.