Good point. I'm looking at options, and those Zigbee boards can run on 24V so it probably makes more sense to go higher volts anyway. Anything with better dependability than the tiny 3V valves in the smart garden valve devices.
Those 3v valves are just underpowered, and they get jammed stuck on because the spring is too wimpy to push it back off when there is wear resistance, or they get stuck off because the coil is too small to push it open with resistance from wear. That's my theory, anyway. I think I get a bit under 1000 on/off cycles or just over two summers out of those valves before they get sticky, based two watering cycles a day.