slipstick:
Depending on exactly which HC-05 you have the specification probably says something like 3.6V - 6V, over 7V prohibited.And you're connecting 2 x Lipo cells to it, 7.4V nominal, 8.4V fully charged.
Can't you see any problem there?
Steve
My HC-05 is 5v version with onboard regulator not the 3.6v-6v
