The unit came relatively quickly here. After I unpacked it and have turned it around, I noticed that something was loose inside. A mounting pin for screws was broken! I have not complained, not only because of a loose screw. To the car battery connected .... plug into the socket ..... finished. The performance data I personally think a fairy tale. If a functioning car battery needs to get to 100% 34 hours. No truck battery! The display of the charge state is running the way into a rather strange sequence. The lights go out one after the other until only MAX (= 100% load) remains. For the price the device is okay. However, I would no longer buy, too time-consuming.