About this replacement
Lenovo Legion Slim 5 14APH8 — 15.52V Li-Polymer Replacement Battery (5B11K39112)
This 15.52V, 4700mAh (72.94Wh) Li-Polymer battery replaces the original cell in the Lenovo Legion Slim 5 14APH8 laptop. It fits all 82Y5 variants of that 14-inch gaming laptop, including CTO and regional builds. OEM part numbers L22B4PA2, L22C4PA2, L22D4PA2, L22L4PA2, L22M4PA2, 5B11K39113, 5B11N45950, and 5B11N46019 are all covered by this cell.
- Legion Slim 5 14APH8 82Y5 series fit: Every 82Y5 variant — CTO, regional, and country-specific builds — uses the same 15.52V four-cell Li-Polymer architecture, the same physical connector, and the same BMS handshake. One cell covers the entire 82Y5 range.
- Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on the Legion Slim 5 platform. The BMS initialised correctly, charge current stepped down normally at the top-of-charge threshold, and no protection trips occurred during CPU-plus-display load testing.
- BIOS battery learn cycle after install: After fitting this cell, run one full discharge down to hibernate cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap on Lenovo Legion hardware.
BIOS reporting poor battery health immediately after replacement
When a new cell goes in, the Lenovo BIOS reads EEPROM data from the old battery's embedded fuel gauge IC and compares it against the new cell's initial readings. The mismatch triggers a false "poor health" or "consider replacing battery" warning in Lenovo Vantage and the BIOS power menu. This is not a fault with the new cell — it is stale EEPROM data from the previous battery influencing the health calculation. One full discharge-to-hibernate followed by an uninterrupted charge to 100% clears the learn cycle and the warning typically disappears within two or three cycles.
Laptop shutting down at 20–30% charge shown on screen
This symptom appears when the fuel gauge IC has not yet calibrated against the new cell's actual chemistry. The percentage shown on screen is based on the old cell's voltage-to-capacity curve, so the reported figure and the real state of charge diverge under full CPU and display load. When the Ryzen CPU spikes under gaming load, the battery voltage drops sharply — the fuel gauge IC sees the voltage cliff as a low-voltage cutoff and triggers shutdown even though the displayed percentage looks safe. Run two to three full discharge and charge cycles to allow the fuel gauge IC to recalibrate against the new cell's actual voltage curve.