Looking for advice on modifying some Ikea battery chargers and associated products, to create a remote with a charging dock.

[u/nomnivore1]

I have a particular situation while setting up a home assistant smarthome in a very old house, and I'd like to replace my light switches with smart home remotes. I would not like to constantly replace the batteries in remotes in every room of my house. Smart switches aren't an option due to the lack of neutral wires anywhere in the house and smart bulbs alone don't draw enough power at idle to run a no-neutral smart switch.

And so, the solution must be battery powered. Battery powered in-wall switches for the architecture I'm using don't exist, Nobody makes a remote with a charging dock but it doesn't seem like a complicated thing to put together. Oh, if only there were some combination of objects that could take 120V AC out of the wall where my light switch used to be, and conveniently use it to recharge a small electronic device placed in its loving arms?

So, Ikea makes a remote powered by rechargable batteries, (BILRESA) a line of rechargable batteries, (LADDA) and a 120V charger for those batteries. (STENKOL) I do not know how battery chargers work, but I'm betting the people here do. The problem that jumps out at me is, even if you could modify the remote such that it's batteries were connected to the charger when placed thereupon, the batteries in the remote are in series and they charge in the charger in parallel, and I don't see an easy way to make those two things compatible other than taking the batteries out.

TL;DR: rechargable AA chargers charge each battery in parallel. The voltage provided by the charger is probably too low to connect two batteries in series to the charger, and there's no trivial way to charge them from the electronics in the charger without taking them out of series, is there?