Just in case you are in the market:
https://hobbyking.com/en_us/turnigy-nano-tech-180mah-2s-25-40c-lipo-pack-5pcs.html
On sale for $13.20. You need to bump the amount up a bit to make shipping reasonable. They are having a sale on nearly everything so easy to find more stuff to add. And even if you only buy a five pack with shipping that works out to $4 a battery, use twice and as cheap as a 9 volt with better reliability in my mind.
Tony
https://hobbyking.com/en_us/turnigy-nano-tech-180mah-2s-25-40c-lipo-pack-5pcs.html
On sale for $13.20. You need to bump the amount up a bit to make shipping reasonable. They are having a sale on nearly everything so easy to find more stuff to add. And even if you only buy a five pack with shipping that works out to $4 a battery, use twice and as cheap as a 9 volt with better reliability in my mind.
Tony