I've heard and read many a time over recent years that the way batteries should be charged has changed. I've always been someone who lets devices run right down as low as I can before charging them back up to 100%. With one or two exceptions, this strategy still seems to work remarkably well for me, regardless of what others say. My previous Nokia phone would run for days under each charge, my current Android one goes five days or more between charges (I'm a light phone user), but conscious of this continual hounding from random people who may or may not be tech-inclined, and having both a laptop and a phone that offer flexi-charging options, I decided maybe I should change that strategy. So following a similar setting I just made on the Android phone, I set the Flexi-charging option in my Clevo laptop BIOS. It only allows adjustments in increments of 10%, so I set the lower Start point to 50% and the upper Stop point to 90%. Though I have a laptop, I almost always use it sat at my desk with it plugged in and hooked up to a bigger monitor and other peripherals. I like the versatility of taking my main PC with me on the odd occasion I go and stay with friends or family, but I don't frequent cafés with wifi because I'm not a hipster, and I'm terribly uncomfortable having the laptop on my lap or anywhere else. So for most of its life, it is plugged in being constantly topped up to 100%. Once or month or so I try to unplug it and use it on battery to let the battery drain and refill. When I do that, the laptop invariably throws a fit and suddenly warns about critical battery level even though it's still at about 45%, and switches off within a few seconds. I get these weird messages in my notifications: Message from syslogd@linux at Jul 3 15:34:04 ... kernel:[ 87.166486][ C0] Uhhuh. NMI received for unknown reason 20 on CPU 0. Message from syslogd@linux at Jul 3 15:34:04 ... kernel:[ 87.166498][ C0] Do you have a strange power saving mode enabled? Message from syslogd@linux at Jul 3 15:34:04 ... kernel:[ 87.166500][ C0] Dazed and confused, but trying to continue I don't think there's anything strange about my power-saving settings, it seems more likely the continual charging fools something in the subsystem as regards the actual charge level. Using flexi-charging is supposed to make battery reporting LESS accurate, but it's clearly already problematic. And usually, once I plug the laptop back in, the charge level shows back at 45%. So now having changed the BIOS setting, I see in Plasma (5.24) that the battery icon shows permanently in the system tray, because it's being constantly topped up... to 90%. I thought maybe what would happen is that it would decharge to 50% and then the charging would kick in and bring it back to 90%. I don't know if that would be better or worse, I can't see as hundreds of charge cycles will help, and in any case there's no options to set it to behave any differently, that would require additional software. Some of you must have a similar setup. What have your results been like with whatever charging strategy you use? I've had this laptop three years now and according to the Plasma Info Centre the battery health is at 94%, so it hasn't weathered badly. Should I abandon this experiment and disable the flexi-charging? The battery is replaceable anyway so if I really needed maximum battery life one day on this machine I could get another one. gumb