I noticed my batteries (the 2 that came in the kit) were getting nasty looking around the threads and air holes plus I think they were stopping up. I think I read somewhere here that they could be cleaned with alcohol; so I used a toothbrush and isopropyl and cleaned the ends of the batteries and blew the air holes out with compressed air. The funk is gone and they look clean, but however one doesn't work anymore, wont charge nada. Customer Service is going to replace it but I'm curious of the dos and don't about battery cleaning... any ideas or comments out there?