So, I had my Steam Deck plugged in overnight.

I went to play it this morning, and when I unplugged it, the battery reads 90%.

I plugged it in, and it immediately reads as full.

I unplug it, straight back to 90%.

Its my understanding that manufacturers typically reserve a certain portion of the battery capacity to account for degradation over time - freeing up reserved capacity as existing capacity wears out.

However, I thought that typically the reserved capacity isn’t used when calculating whether or not the battery is fully charged.

Any ideas what might be going on? Is this even something to be concerned about?

I tried rebooting, and nothing changed.