Why is my Dell computer battery not charging?

Hello,

my battery has not worked properly for a long time.

At first it all started with the error "Mains operation, the battery is not charging". I then searched for and found solutions online: uninstall the driver, shut down, disconnect the power supply, remove the battery, hold the start button for 20 seconds, insert the battery, insert the power supply, start up. The whole thing also worked for a short time. However, the error kept coming back (sometimes after a few hours, sometimes after a few days).

Now he only shows "33% remaining (network operation). The above-mentioned procedure no longer works either. I had already ordered a new battery, but the same problem occurs with this one. I can therefore rule out a defective battery.

When I read out the status via F2, the Health "excellent" displayed and at AC adapter "unknown". Also via F12 only the error comes: "The AC power adapter wattage and type cannot be determined. The battery may not charge."

According to Google, the cause remains the power supply itself, which, however, has no visible kinks or damage. In addition, the network operation works without any problems. Can it still be because of that? I don't want to buy more spare parts if I don't need to.

Inside everything looks ok too. Only the red-black cable that goes along the battery has a pressure point and a minimal hole (hardly visible to the naked eye). Can it also be because of that? Or does the cable have nothing to do with the battery? After all, it is in the mainboard and not directly on the battery.

I am thankful for every help. Since the notebook is pretty well equipped, I wouldn't want to replace it with a new one.

Thank you in advance!