5 minutes is a very brief runtime. And, if this is the original battery for that 12-year-old laptop, it's unsurprising that the battery is at end of life. I suspect that after that the result will be the same, because the battery is almost dead, but it's worth a try. You can test the battery: Open an Administrator CMD prompt (CMD, run as Administrator).Paste this command, and then press Enter:powercfg /batteryreport That will show a figure for the designed battery capacity (when new) and the current ("full charge") capacity. Parts-People sells genuine Dell batteries for your laptop.
I have this E6520 with a 97wh battery, but the battery icon led is blinking in yellow color, in the taskbar there is the message "no present battery" also in BIOS, but the wierd thing is, when i unplug the powrr cable, it will stay powerd on the laptop for like 5 minutes. I tried to uninstall the battery drivers and install them again, latest BIOS from dell, drain all the power from laptop then put back everythingk and power on, still the same problem.  Any solutions ?
E6520 97wh battery "no battery present"