Sleep and battery power for remote control

I’m making an IR ‘blaster’ for the various devices in the loungeroom - screen, amp, lamps etc. It’s designed to be just a single button to turn everything on/off with a series of IR codes.

What’s the best way to power this? I want to use a Wemos D1 mini 8266 so that in the future I can upgrade it to use MQTT over WiFi, and because they are a nice small board. The case I have for the remote is quite small.

I know how to put an 8266 to sleep, perform an action on wake then go back to sleep; at this stage that’s all that’s needed.

I was thinking of one of the common step up DC-DC boards and a CR123A battery, is there a better way to be doing it? The DC-DC conveter would be connected to the battery all the time, I can’t see a way to avoid that. Or is there an agreed on best method of powering a loungeroom remote like this from a battery?

If you had more space you could use two batteries in series, you would avoid the DC-DC converter.

Wouldn’t I still need a regulator in there, so would have to be extremely low voltage dropout ?

Not if you feed the board through the Vin pin and so we can work the internal regulator.

I found these tiny LiPo cells, are they likely to be up to the task of an infrequent kepress and IR pulse?

It will work well, but I see it as low capacity, calculate the consumption of your project well to see how long it will last before recharging.

As it’s a remote it’d get a few pulses of activity per day lasting well < 1 second. I know an 8266 can draw a bit of current esp when using WiFi. It’s just conjecture on my part atm I know, my apologies, I’ll breadboard the circuit and do some measurements. I was just fishing around to see what sort of things are possible and/or recommended. The series cells might remain a possibility, it’s a little French polished wooden box I’m using and may be able to chisel out some more room inside, but the Vin pin wants 9V - 12V from what I read?

Well, rather it supports 7 / 20V. Then we return to the starting point, we need a step up DC-DC boards, or put two of those lithium batteries in series using a charger / regulator similar to this:
As you can see, it is so tiny that I think you would have no difficulties installing it in the small box of the IR remote.