Thomas - Here’s what Apple states on battery lifespans [https://support.apple.com/en-us/HT201585|Determine battery cycle count for Mac notebooks]
As you can see Apple’s max cycles for your system is 1000 you’ve over shot it by 383 more cycles!
Time for a new battery ASAP!
Here’s the needed battery [https://eustore.ifixit.com/en/Parts/MacBook-Parts/Macbook-Pro/13/Retina/Early-2013/MacBook-Pro-13-Retina-Late-2012-Early-2013-Battery.html] and here’s the guide you’ll need to follow [guide|90275]