HP Power Adapter AC 90W 7.4mm Tip 19VDC Output - C6 3-Pin AC Input

Enables you to operate your notebook or charge the battery from electrical power outlets.

Full protection for the notebook computers. Reliable protection circuit: with over charge, discharge protection, and over current and short protection.

If you are running your computer on AC power with a battery installed, this adapter charges the battery (if needed) and maintains its charge. When the system is off, the AC adapter will charge the battery and then maintain its charge.