Lenovo IdeaPad L340 11.25V Replacement Battery 5B10T03402

Lenovo IdeaPad L340 / V155 Series — 11.25V Li-Polymer Replacement Battery (L18M3PF2)

This 11.25V, 3150mAh (35.44Wh) lithium-polymer battery replaces the original cell in the Lenovo IdeaPad L340, IdeaPad L340 15iWL, V155, and V155-15API. OEM part numbers covered include L18M3PF2, L18C3PF2, 5B10T03402, 5B10T03404, 5B10W67321, and SB10W67268, among others. If your laptop no longer holds charge or shuts down unexpectedly, this cell restores portable operation to the affected unit.

• IdeaPad L340 and V155 platform fit: These models share the same 11.25V three-cell Li-Polymer voltage rail, connector pinout, and BMS communication protocol — which is why a single SKU covers the full L340 and V155 range. The BMS handshake and EEPROM profile match across these variants.
• Bench tested on actual hardware: We cycled this cell on an IdeaPad L340 15iWL unit. The BMS accepted the new cell without rejection errors, the charge controller stepped through trickle, CC, and CV phases correctly, and the protection circuit tripped at the expected over-discharge threshold.
• BIOS learn cycle after installation: After fitting this cell, run the laptop down to hibernate-cutoff under normal use — not idle — then charge uninterrupted to 100% without resuming use mid-cycle. This resets the BIOS battery learn cycle and clears the inaccurate health warning that typically appears after any cell swap on IdeaPad hardware.

Why the IdeaPad L340 shuts down at 20–30% after a battery swap

The L340's fuel gauge IC calibrates against the cell's discharge curve. When a new cell goes in, the IC is still reading the old curve and misjudges the remaining capacity. Under combined CPU and display load, the actual cell voltage drops faster than the gauge predicts, and the system hits the low-voltage cutoff while the OS still shows charge remaining. Two to three full discharge-to-hibernate and full-recharge cycles recalibrate the IC against the new cell's actual curve. After calibration, the percentage reading and the physical cutoff align.

New cell not charging above 80% on the IdeaPad L340

This is a BIOS-level charge limit, not a fault with the replacement cell. Lenovo's Conservation Mode — enabled through Lenovo Vantage or a BIOS setting — caps charge at 60% or 80% to reduce cell stress during extended AC use. The battery itself is functioning correctly; the charge controller is simply following the firmware instruction. Open Lenovo Vantage, navigate to Power, select Battery Settings, and switch from Conservation Mode to Normal Mode — the cell will then charge to 100%.