HP 6-cell Lithium-Ion Primary Battery. Stay connected and be productive wherever your work takes you with HP tested and validated primary batteries. This 6-Cell Lithium-Ion battery has a capacity of 52 WHr which enables you to work seamlessly while on the go. HP Fast Charge Technology Charges the battery up to 90% within 1.5 hours when system is off. No need to sacrifice performance, productivity or convenience.