Replacement 3-cell laptop battery BTI L77991-005 for HP 850 G7 / 855 G7 / 850 G8 / ZBook Firefly 15 G8, 11.55V 5850mAh (68Wh), black

BTI replacement 3-cell lithium-ion battery for select HP laptops, compatible with models such as HP 850 G7, 855 G7, 850 G8 and ZBook Firefly 15 G8. This battery replaces OEM part numbers 28Y92UC, CC03XL, HSTNN-DB90, L77622-2C1, L77622-2C2 and L77991-005. It is black, supplied as a single unit, and provides 5850 mAh (68 Wh) capacity at 11.55 V.

Advantages

The BTI replacement battery uses lithium-ion technology to deliver reliable power and maintains compatibility with the listed HP laptop models and OEM part numbers. With a rated capacity of 5850 mAh (68 Wh) and nominal voltage of 11.55 V, it is intended to restore portable operation times comparable to original batteries while fitting the same mounting and connector specifications.

Suitable for

• HP EliteBook/ProBook 850 G7 and 850 G8 series
• HP 855 G7 laptops
• ZBook Firefly 15 G8 mobile workstations
• Replacing OEM batteries with part numbers 28Y92UC, CC03XL, HSTNN-DB90, L77622-2C1, L77622-2C2, L77991-005

Key specifications

• Battery technology: Lithium-Ion (Li-Ion)
• Capacity: 5850 mAh / 68 Wh
• Voltage: 11.55 V
• Cells: 3-cell
• Color: Black
• Units included: 1 pc

How to use

Power down the laptop, disconnect the AC adapter, and remove the bottom cover according to the laptop manufacturer's service instructions. Remove the existing battery by unscrewing and disconnecting its connector, then install the BTI replacement battery in the same orientation and secure it with the original screws. Reattach the cover, reconnect the AC adapter, and charge the battery fully before normal use.

Recommendations

Use the replacement battery with compatible HP models only. Follow manufacturer safety guidelines: avoid exposure to heat, puncture, or water, and dispose of the old battery in accordance with local regulations. If uncertain about disassembly, have the battery replaced by a qualified technician.