Does anyone know where I can find a CMOS battery replacement for a Dell XPS 15 (9575)? I'm looking to replace it after some technical issues. Any help would be greatly appreciated

How do I calibrate the battery for the buds+ case if I replaced the battery for it. If so, how long do I calibrate it for? I previously replaced the batteries for the earbuds themselves and was informed to calibrate it until fully charged plus 2 hours, then let it drain completely, then recharge it to full. Does this sound right or am I off for the battery case?

I replaced the battery for the TomTom 1535 Go Live and after waiting 2 hours to let it charge up, it still doesn’t seem to turning on. What is the problem that I can be facing here? I’m hoping to not spend a lot of money to try and replace it as I’m trying to resell it. The funny thing is that it was working fine before I had to replace the battery.