It doesn't fit on the battery well
To start off, this product is not a good idea. DeWalt 20V batteries have no internal protection against over-current, high-temperature, or reverse-polarity. Neither does this adapter. If you happen to short-circuit the connectors, or connect the cables backwards, you could easily get a thermal runaway. That would likely destroy the battery, or even cause a fire. Also, car electrical systems are designed for 12-15V, not the 18V that DeWalt "20V" batteries actually deliver. While unlikely, it's possible to damage vehicle electronics. There's no specification for how many Amps a DeWalt battery can deliver. It's likely around 20-40A, depending on the battery configuration (DeWalt tends to use good quality cells). With aftermarket batteries - who knows? That's pretty low compared to what it takes to crank a car engine. If you want a jump-starter, get one designed for that purpose and has appropriate safety features. That said, if you still want to try this product, be aware that the connector doesn't fit properly. It is way to tight. I tried with several batteries (name brand and aftermarket) and was barely able to slide the connector onto the battery. I could only attach it by wiggling and pounding it into place. Once on, it was quite difficult to pull them apart. On the flip side, other parts appear to be of good quality. The cables are 8ga stranded copper with silicone insulation. The clamps have copper jaws that mate well. Spring tension is good. The connector is useless, but I may re-purpose the cables and clamps. Read more
