We have a Lincoln Lowrider with 6 batteries in the trunk. This charger not only charges batteries but also restores them. I don't know the details of how he fixes them so I can't go into detail but it should save us some money on buying new batteries. It fits snugly between batteries and is small and powerful. I've only used it once or twice. We keep it in the car because a lot can happen to the batteries every day. It's nice to have tools that can quickly charge and repair batteries.