Software to hold battery at 50% charge level [closed]

Solution 1:

To push Sparr's comment into an answer, he's completely right. Charging circuitry is typically pretty dumb and can't be controlled via software. There may be a hardware solution that would go between the wall socket and the power adapter, but that's unlikely.

As a man who troubleshoots the power boards in old laptops for fun, I haven't seen this sort of feature (or chip to support that feature) in any brand before. There doesn't seem to be a generic solution yet. Maybe the industry will change.

Solution 2:

On recent Lenovo Thinkpad laptops you can use the System Management API tools to set the charging threshold and limit, in the same way that the Sony tools do.