I have had two passthroughs die in the last 3 weeks. I am not sure what is going on. I will attach them to my laptop to charge, and then once charged I take them off and use the power from the inline battery for a while, periodically plugging them into the computer to charge again. I have had one in my car that I use the same way with my usb adapter. I have not had a problem with that one after 6 weeks. I'm not sure why these are dying on me. I have taken the batteries out, and by happy coincidence they also work in my cigar. Both of the batteries are working fine, so it must be in the wiring, but I don't understand what would be causing the short. Would there be a difference between the power from my laptop, and that from the adapter in the car?