Battery for Lenovo XiaoXin Air14-2019 L18C4PF3 M4PF3 L18C4 L18M4PF4, 11.55V 45Wh, Compatible with Ideapad S540-14API, High Capacity, 12-Month Warranty

**Product Description**
Upgrade or replace your worn-out laptop battery with this premium-grade replacement specifically designed for Lenovo XiaoXin Air14-2019 and compatible Ideapad S540-14API models. Whether your original battery no longer holds a charge or drains too quickly, this high-performance 11.55V 45Wh battery restores your laptops portability and productivity.

**Important Voltage Warning**
Please verify that your original battery voltage is 11.55V before purchase. Using an incorrect voltage may cause damage to your laptop or battery. This replacement is NOT compatible with 7.6V, 11.1V, 14.4V, or 15.2V systems.

**Compatible Models & Part Numbers**
- Laptop Models: Lenovo XiaoXin Air14-2019, Lenovo Ideapad S540-14API, Lenovo Ideapad S540-14IWL
- Battery Part Numbers: L18C4PF3, M4PF3, L18C4, L18M4PF4, L18M4PF3, L18L4PF3, L18L4PF4, L18C4PH3, L18M4PH3
- Note: Always double-check your laptops model number and battery compartment label.

**Specifications Table**
| Specification | Value |
|---------------|-------|
| Battery Type | Li-ion |
| Voltage | 11.55V |
| Capacity | 45Wh / 3900mAh |
| Cells | 4-cell |
| Color | Black |
| Connector | 6-pin (same as original) |
| Dimensions | Approx. 270 x 70 x 5mm |
| Weight | Approx. 220g |
| Warranty | 12 Months |

**Comparison Table: New vs. Old Battery**
| Feature | This Replacement Battery | Old/Degraded Battery |
|---------|--------------------------|----------------------|
| Capacity | 45Wh (full capacity) | Often below 30Wh |
| Charge Cycles | 500+ cycles | 200-300 cycles |
| Safety Protection | Overcharge/Overdischarge/Short-Circuit | May lack or degrade |
| Warranty | 12 Months | Usually expired |

**Installation Tips**
1. Power off your laptop and unplug the AC adapter.
2. Remove the bottom cover (use a plastic pry tool to avoid damage).
3. Disconnect the old battery cable from the motherboard.
4. Remove the screws securing the old battery and lift it out.
5. Insert the new battery, secure with screws, and reconnect the cable.
6. Replace the bottom cover, plug in the charger, and power on.
7. For best performance, fully charge the battery before first use.

**Package Includes**
- 1 x Replacement Battery
-
- 1 x Installation Guide (digital)

**Note**
This is a compatible replacement battery, not an original Lenovo product. It is manufactured to meet or exceed OEM specifications. If you have any questions about compatibility, please contact us with your laptop model and original battery part number.