After a few days of "regular use" with mine, gotta agree that the battery life is not good. Very reminiscent of the OG Switch in 2017 (before they launched the units with the better battery). It also seems to take FOREVER to charge, like hours. Compared with something like my phone that can charge in about 45 minutes from fully dead, it's pretty much a "put it on the charger at night and in the morning it'll be charged" thing.
I know it'll deteriorate the battery health over time, but I had to turn off the "charge to around 90%" setting, because the word "around" was doing some heavy lifting there. So far it has actually charged overnight to 72%, then 78%, then 75%, and finally this morning it was 82% - so I think that setting is either broken or not correctly calibrated. With as bad as the battery life on this thing is, sacrificing another 20%-25% charge isn't worth the trade-off to me.
Maybe I'll try that setting again after this gets a few firmware updates.