The 1% battery after installing Big Sur is driving me crazy too (Coconut shows 92.8% and 212 cycles, but no charging whatsoever). It happened right after the public release of Big Sur. Installed without issues, but suddenly, when on a video call, my MBP 2016 switched off. No warnings of low battery, just instant-off. Tried SMC and NVRAM resets but no result. Diagnostics showed PPT006. Reinstalled Big Sur (as was advised by an Apple service employee), downgraded to Catalina, re-upgraded to Big Sur, but the problem remained. So the Apple Service employee told me to service the battery, which I did at an Certified Reseller. Paid the 79 euro's, because the Service Employee told me a new battery would cost 139 euro, so I decided to go for it. After a few weeks, the Certified Reseller said it would cost 750 euro to fix it. Say what? The trade-in value is 460, so no way. So they sent it back. The Certified Reseller stated that the Apple Service Employee shouldn't have mentioned the 139 cost of battery replacement and the couldn't do anything for me. And here I am with a MBP that needs power at all times and I lost 79 euros. If Apple would only admit these problems are not a user's fault and offer me a realistic trade in value, I would do it and go for a M1-MBA. But since Apple is playing hide and seek on this matter, I'm afraid to buy the M1-MBA and trading in my MBP-2016, only to discover that Apple is very sorry, but can only offer me 1 euro for a MBP with PPT006, caused by Apple. That's my nightmare. So I can only wait until Apple admits their mistake. So come on, Apple! Reach out to all users that you've left in the cold and be generous!

On day 1 of the public release of the final version of Big Sur, I updated my MBP 2016 (4 ports, Touch Bar). Installed great, but while making a video call, the system shut off completely. Battery drained while on the charger, but it failed to charge. Battery service required. Reset SMC, PRAM, went back to Catalina, but no success. Reinstalled Big Sur. No improvement. As soon as I unplug the cable, it dies. Diagnose gives PPT006. I was advised to send it in, which I did. I’ve been offered a 750€ repair, while the trade-in value is only 460. And I just tried to install Big Sur on a machine that ran flawless until then. I do hope Apple acknowledges there’s a big problem with Big Sur and offers a reasonable follow-up.