I just stumbled upon this which shows the best way to orient the SmartThings v1 hub for improving zwave performance…
not sure if there is an updated image for gen2
In another topic I posted about a z-wave siren, WA105DBZ-1, that can act as a repeater when power supply is attached. Key point is that the siren uses 12V DC power, not 120VAC… more on that in a sec:
https://www.amazon.com/GoControl-Z-Wave-Siren-Strobe-WA105DBZ-1/dp/B00MNYSEKY/ref=sr_1_1?ie=UTF8&qid=1505213733&sr=8-1&keywords=WA105DBZ
https://www.nortekcontrol.com/pdf/manuals/WA105DBZ_install.pdf
My thought was to use this siren in a weather proof enclosure, and one of two low voltage ways to power it:
1- A 12V battery with solar panel to keep it charged
2- 12VDC power adapter (included with siren), connected to buried landscape light cable , connected to the WA105DBZ-1 halfway to garage. You could test this above ground by cutting the included 12V adapter’s cable and inserting the long landscape cable inline, you could probably even do 2 hops if needed.
DISCLAIMER - I haven’t tested any of this 