Lyric Thermostat - External Transformer

[Abu3baid]

Hey everyone, I have been so busy the past year I haven't had time to play golf or log on, but I am on vacation now and finally spending time at my new house and I am facing an issue that I am sure someone here can help me with.

some pictures first

 

I have 6 zones each with its own thermostat, and only one of them is connected to the Furnace and Air conditioner.  The issue I am having is that the batteries run out quickly and since I'm not here most of the time I can tell be continuously changing batteries.

The idea of connecting each to the Furnace or AC is out of the question, so I was looking it up and the idea of having an external transformer for each of them seems like a great idea!  problem is I don't know what I'm doing.

Is this even an option that would work?

If I found the transformer where would I connect the two wires on the thermostat?

what is the best transformer?  where do I go get it?  should I just get them and have an electrician do it?

Thanks guys!