Your charger is not able to support your system when your apps need full CPU & GPU performance. Your system will conk-out corrupting your drive!
I strongly recommend you property fix your system. As this is in a fragile state both physically and data wise (corrupted drive)
A common issue in this series is the back shell becomes unglued to the lids mid frame and in some cases the frame its self cracks when in this state, It’s worth the gamble to fix the lid. Follow this guide to take the LCD panel out [guide|3574]
[image|2175847]
And get a new battery! [product|IF161-105-4]
For the investment of 100 bucks this is worth it! Even if you only use it for a year or two waiting to see what Apple is upto with the coming Apple Silicon systems.