Bought this adapter and it worked great in my Dewalt drill and impact driver. Left it and a battery attached in my drill like I would with the old style batteries. When I went to use it a few weeks later the battery was DEAD, as it wouldn't even take a charge. Fortunately, watched a YouTube video and jumped the dead battery from another battery to give it enough charge that the charger would 'see' it and charge it fully. Now I remove the battery from the adapter after every use.