@alexsh1 the reason i am using the 18650's is the fact i have a steady stream of them coming in for my large battery packs. I have a couple hundred that aren't dead but just aren't quite up to to the standard i am putting in my big packs.
@nca78 I don't use ATAES132A. I put it in just in case I wanted to invest some more time using it.
I now just use SimpleEncryption, it's secure enough for my purpose atm.
(since the area I live in uses KAKU a lot, an insecure 433MHz lightswitch, I don't think anyone would be bothered to hack my temperature sensors. I found 163 433Mhz devices when I left domoticz logging for a couple of days.)