Stop battery usage [Ubuntu 18]

Please, tell me how can I stop the battery of being used by the computer completely.

There is no method for that from within Ubuntu: a battery creates a loop between the power source and the motherboard so it is all hardware. You will need to physically remove the battery from the system.

Should I remove the drivers of the battery

Batteries do not have drivers. Anything inside Ubuntu is used for analytics purposes (percentages, life span, etc)

One extra remark: make sure the power cord is attached to the system with some tape; if the connector is as fickle as what I have now it will kill your system if is disconnects.

A solution which for now works is, from Settings > Notifications I have completely switched off any notifications, clicking Notification Popups. The lag disappeared, the notifications as well. The problem is that none of my attempts to stop just the low-battery notifications locally worked. Hence, this solution prevents other apps' ones to be displayed, too.

If I see this solution not working in the future or I find a better one I will update this answer.

The battery is in the laptop.

@Rinzwind is technically correct - batteries don't have drivers, but they do have controllable firmware. This firmware accepts orders via ACPI(Advanced Configuration and Power Interface). You could cut your OS off from information on what the battery is doing by unloading all ACPI kernel modules(acpi=off kernel parameter) or by specifically unloading the battery acpi kernel module(with modprobe). Both solutions courtesy of https://wiki.archlinux.org/index.php/ACPI_modules.

However, messing with ACPI is a bad idea. ACPI is useful for more than just battery control - it controls processor states(you would most likely need to change your processor scheduler), fan speeds, screen brightness, the power button (for shutting the computer down if the OS crashes irrecoverably), temperature sensors. Turning ACPI off is like unfastening your seatbelt.