If your bios is getting reset it’s possible your system uses a cmos battery and it is dead. It’s separate from the main battery and handles date/time/bios.

Just look for something that looks like a button battery inside your laptop. Sometimes it’s wrapped in plastic. My old Dell had it wrapped in rubber which held the wires in place and had a special connector.

Newer systems don’t have them - they just rely on the main battery. But if yours is losing time/settings you might have one with a separate battery. It’s usually a cr2032 or similar.

I’ve noticed that, at least in the US, that the blades are MUCH cheaper online. Like my local store sells 1 blade for $20, but I can buy 20-30 blades for the same price online.