Feeding Fibaro relay switch 2x1.5kw with 24v DC

[pepe6859 0]

On the 2x1.5kw relay switch datasheet I can see it have <0.8 watts power consumption.

Is it average? Polling?

I would like to feed the relay switch "coil" from 24v small battery. I have mA/h limitation so this info is crucial for the battery life time calculations.

I have no possibility of 220v on the selected switch location and battery size is also limited. No mini mote or other transmitter desired for this action.

Edited: Battery setup give 40 mAh. Then Fibaro Switch takes 0.8watts = 0.333333 A

Battery life time = 40/0.333333*0.7 = 840 hours

Thanks for any help in this matter,

[j.nowacki 5]

pepe6859, Realy Switch can work with 24V DC, but remember that it is mains-powered device by default and therefore it takes place in routing and constant polling, which will reduce battery life significantly. Also when battery dies, the routing table will become obsolete and traffic in Z-wave might rise.

[UrSv 6]

Edited: Battery setup give 40 mAh. Then Fibaro Switch takes 0.8watts = 0.333333 A

It won't actually work that well in real life but I do hope you are talking 40 Ah otherwise you'll be a bit off in calculations.

40 mAh is 0.040 Ah

0.8 W at 24 VDC is about 0.033 A/33 mA and not 0.333 A.

That would give you about 40/33 hrs i.e. 1 hr 12 minutes but you won't get that much. If it was 40 Ah (a small car battery at about 10 kg) then that would work longer.

[pepe6859 0]

Thank you j.nowacki and UrSv for your replies.

J.nowakcki, I was also thinking to feed the Relay Switch only when needed (same time when pushing the button) but not sure about polling consequences when device not reporting to controller and how long it will take to the controller and device to re-pairing). Now I understand it is not possible right?

UrSv, Thak you for the correction in my wrong calcs.

[ Added: 2014-09-13, 14:50 ]

A decision has been made! Monday morning works will start to install flexible conduit embedded in the brick wall to run 220v cables up to Relay Switch location (this is Spain, no dry walls). Works will take two days repainting included and some of my $$$ but it will be a very reliable installation.

Thanks for your comments guys!!!

[j.nowacki 5]

pepe6859, it sure will be more stable than battery supply. And range will benefit from such solution also!