I did buy this product to maintain support a car (Lexus) that rolls just by feeding the battery via the cigarette lighter. On this electronic car packed, it does not work, or rather the car goes crazy: Emergency control the car on key non-detection (even if the key is present). Fortunately, this product comes with many branching interface, so I replaced the cigarette lighter by clamps and I connected directly to the battery. Nickel. Do not worry if the light does not turn on when you turn on the power: you must also connect the battery to turn. This is a good product for which does not express its battery charging (1.2A reload the intensity of a big battery in several days ...).
