I present to you the Franken-flora:
7dB increase in signal strength (from -90 to -83dBm in the centre of my lawn). Was supposed to be a 9dBi antenna but matching losses and Chinese advertising hyperbole took the other 2 dB.
1800mAh battery that should last about 16 months (I got 2 months from a 220mAh CR3220).
Waterproof enclosure for outside use.
I’ll be surprised if it lasts a month.
Edit: holey shatballs bitman!
RSSI is now a steady -66dBm. I can move it further away from my irrigation controller and out of the centre of the lawn (which was a PITA to be honest).