emonTH: pulse AND one-wire temperature measurement; AC with battery backup?



I'd like to monitor hot water usage. Flow rate via pulse output flow meter and incoming/outgoing temperatures using the one-wiresensors clamped to the copper pipes to and from a heat exchanger.


Q1) Can I do this using the emonTH rather than an emonTx V2?

It's the same hardware base and has the two inputs I need; right? (forgive the silly question: I usually work on the water side)


A slight complication is that the heat exchangers are on thermal stores are located in social housing with prepayment electricity meters: AC power availability is not guaranteed and I'd like to leave them there for 6 months unattended.

Q2a) Would it be practical to fire up the emonTH (or emonTx V2) in response to an interrupt from the pulse output flow meter, read the temperatures, keep logging pulses and temperatures every second or so whilst they are arriving/hot water is being used then go back to sleep when it's been 10 seconds and no data has been received? Is this likely to give acceptable battery life if I were to use D-cells?

Q2b) Do you know of any "USB UPSes" that are inexpensive and suitable for running an emonTH or emonTx V2 in a permanently on manner for a day or two without AC power?