I just received my Bose aviation headset from a factory overhaul. Outstanding service and customer support! A lot of parts were replaced and all was covered under warranty. I owned it for 4 years. Flown nearly 2K hours mostly with lithium batteries because I could squeeze more operational time from them. In the manual Bose specifically mentions alkaline batteries which, to be honest, I somehow missed. Maybe that's why my ANR started acting recently. Anyway don't use the lithium batteries in your Bose headsets.
