It was my dealer that gave the advice for leave it charging for 6h after reaching 100%. I think he also mentioned to charge via wall socket. So maybe this is one more option for you.
As I sadly don't have much time for listening music these days, my player hasn't reached the anonymous 13% (when my player was shutting down), after my 6h plus charging. I will report back for sure, when time has come
Final update ... leaving the unit charging an additional 6 hour past 100% to reset the battery indicator doesn't work. In my test I left the unit charging 18 hours after 100% using an A/C wall charger rated at 5V & 2.4A. My QP1R still has a screwed up battery indicator. This morning it read 69% when leaving the house and died after 15 minutes. When I got to work and plugged it in to recharge it read 34%.
Can I make a software suggest? Would it be possible to add a 'Usage Timer' .. in other words keep track of the hours the unit has been playing? With a manual reset. No need to have this 'timer' tied into the charging/battery part of the software. This would be an additional way of knowing when to recharge. This seems easier to do then fixing the battery indicator.
My problem is, I am old, and have issues keeping track mentally of exactly how long the unit has been on.
On another point, I will be receiving 2 of those new Sandisk 256GB micro cards this weekend. You know where they are going ... don't you. I have filled up the 200's that are already in the unit. I should be able to hold my whole library of 16,000 songs now. Life is good ... until I hit the next 20,000 song limit ...
Also coming this weekend is my Schiit Magni 2 Uber ... I'll be trying that with the QP1R
Anyone here ever use one of those modded Fostex T50RP headphones with the QP1R? I'm thinking about getting a mk2 modded version I saw on a site (Argon from modhouseaudio.com)