Thinkpad T530 fails to charge battery

Some laptop batteries have a lock out window that after X amount of cycles, the battery will either go to a modified charge map or block charging altogether - you cannot fix this without replacing the cells and resetting the microcontroller. As such, the first thing I’d do is recommend a new (aftermarket) battery to see if it persists. These are old enough to suspect a lockout based on cycles.

It’s also important to note not all batteries use this protection. The common method is a modified charge map, which is implemented by most of the manufacturers. This isn’t as bad because the pack still works, but it may get naggy about a known problem. I’d take nags and a modified charge map over a lockout because you were unlucky and hit the lockout threshold. The Latitude series will let you run them until they no longer accept a charge, even if they die within 30 seconds. If they rely on a cycle lockout, I’d question the safety of the pack because that tells me the vendor isn’t confident in their BMS to regulate a high mileage battery.

I would be genuinely surprised if you need a motherboard. I have never seen a ThinkPad motherboard fail outside of nVidia defect T60 series machines. If it’s “dead”, it’s usually because someone forgot the SVP and a perfectly working board was killed over a password.