CS03XL Battery 3900mAh for HP EliteBook 840 G3 G4 / 848 G3 / 850 G3 G4

Your HP EliteBook 840 G3, G4, 848 G3 or 850 series no longer holds a charge or shuts off the moment you unplug? This CS03XL Li-polymer battery is the exact match at 11.4V / 3900mAh, ready to slide into the internal battery bay.

Specifications

• Model: CS03XL
• Voltage: 11.4 V
• Capacity: 3900 mAh
• Chemistry: Li-polymer
• OEM codes: HSTNN-IB6Y, HSTNN-DB6U, 800231-1C1, 800513-001, 800231-141
• Fits: EliteBook 840/848/850 G3, 840/850 G4, 745 G3/G4
• BIOS-friendly: charges and calibrates immediately on install

Symptoms of a faulty part

• Charge drops rapidly below 50%
• Laptop shuts off the instant the charger is unplugged
• Windows shows 'Plugged in — not charging'
• Battery reports <50% design capacity in HP Battery Check
• Bottom cover bulges from swollen cells

Installation

🟢 Easy · Estimated time: 15 minutes · Required tools: Phillips PH0.
Power off, remove the bottom cover, disconnect the old battery (1 connector + 4 screws) and seat the new one in the exact same position.

Frequently asked questions

Does this battery fit the EliteBook 840 G5?
No, the G5 uses SS03XL with different dimensions — not interchangeable.

Do I need to reset the BIOS after fitting?
Not strictly — let the battery cycle once full/empty for accurate capacity reporting.

Does CS03XL work in the ProBook 640 G2?
No, the ProBook 640/650 G2 uses CI03XL with a different connector.