USB Powered or AC Adapter powered EmonTH?

Getting pretty tired of replacing the batteries in all my EmonTH nodes. Especially since many of them are right next to USB or AC power. Is there any possibility that these will be sold powered by USB or AC adapter?
Any guides on how to convert them to be?
My attic is ruining my rechargable batteries because it gets so hot up there. Maybe I can try lithium AA, but I think USB or AC power would be better.

There is no need to convert them, there is already a screw terminal block with terminals for 5 V and GND. Connect your 5 V from a USB connector, or any clean 5 V d.c. supply, there.

Look at the picture here:

I repurposed a couple of old mobile phone chargers; cut off the plug at the phone end, check which wire is +/- (very important!) and wire it in.

I would be wary of using a “charger” - there’s no guarantee that the output is noise-free, which is why I specified “any clean 5 V d.c. supply”.

See: Not all USB power supplies are created the same - Blog | OpenEnergyMonitor

Oops :neutral_face:

Can you use a cheap usb charger with a suitable capacitor?

Edit: ok, I just googled it, and it’s a whole huge topic…

What sort of battery life are you experiencing? 2 x AA batteries should be good for 4+ years.

It’s no problem to wire direct 5V into the terminal block if you wish to hardwire. The terminal block connections are labelled on the PCB.

I can recommend eneloop rechargables. They are much better lasting than other rechargables Ive used. I monitor battery levels and never let a pair drop below 1.9volts because they will go soon after that.
To be honest when the signal is strong a pair of eneloops lasts a long time 6months++. I once had a pair that drained auickly (couple of months) in an emonTH that was outside the house but a slight adjustment so the emonTH had a more direct line-of-sight signal back to the emonPi mostly solved that.

Are you sure it was that, or something else - maybe the emonTH was in a better location regarding ambient temperature? Why I question it is because the transmitted signal strength is constant, and each data transmission occurs once only with JeeLib, so unlike the LowPowerLabs library, there is no attempt to control the transmitted power level according to the received signal strength, or to re-transmit failed messages.

Agree, eneloops are awesome. I wrote a blog post evaluating different batteries for emonTH, eneloops were the best. Normal NiMh rechargeables are almost useless for emonTH since their self discharge rate is 30% per month!