Can I activity this battery with my monitor?

You would be overvolting your VDU by 7.5V. This is VERY BAD.

You can almost guarantee blowing your monitor's quality circuitry this way.

Sophisticated electronics like flat-panel displays have very precise power requirements. Normally, the power circuitry has massively low tolerances for deviation.

Whether you feed it anything other than what it was designed for, you'll easily destroy it.

Go out and get a proper replacement arranger. It's not worth blowing a $200 monitor because of a $10 power adapter.