Dell XPS 13 9315 Replacement Battery 11.55V 4050mAh YM15G

Dell XPS 13 9315 Series — 11.55V Li-ion Replacement Battery (YM15G)

This is an 11.55V, 4050mAh (46.78Wh) Li-ion replacement battery for the Dell XPS 13 9315 series, including models P1708LTW, D1705S, C0NNP, and WP01KR. It replaces OEM part numbers YM15G and G9FHC. The cell fits the slim chassis of the XPS 13 9315 and connects via the original board-side connector with no hardware modification.

• XPS 13 9315 platform compatibility: These 9315 variants share the same 11.55V three-cell architecture, identical connector pinout, and the same BMS handshake protocol. One battery SKU covers all listed models because Dell did not change the power rail or communication bus across this production run.
• Bench tested on actual hardware: We ran this cell on an XPS 13 9315 board and confirmed the BMS handshake completed cleanly — charge controller accepted the cell, reported state-of-charge without error flags, and held the 11.55V nominal rail under combined CPU and display load.
• First-cycle conditioning on the XPS 13 9315: After installing, let the battery discharge fully until the laptop hibernates, then charge uninterrupted to 100% without unplugging. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap on this platform.

BIOS reporting battery health as poor immediately after replacement

The XPS 13 9315 BIOS reads health data from the old cell's EEPROM and compares it against the new cell's reported parameters. A fresh cell has no charge-cycle history, so the BIOS flags a mismatch and displays a health warning. This is not a fault with the replacement cell — it is a firmware artefact. Running one complete discharge-to-hibernate followed by a full uninterrupted charge clears the stored data and lets the BIOS recalibrate against the new cell's actual profile.

Laptop shutting down at 20–30% charge shown on screen

This happens when the fuel gauge IC still holds calibration data from the old, degraded cell. The percentage shown on screen no longer maps accurately to actual cell voltage, so the laptop hits the low-voltage hardware cutoff before the OS fuel gauge reaches zero. The fix is two to three full discharge-and-recharge cycles — each cycle gives the fuel gauge IC new reference points against the replacement cell. After the third cycle, the displayed percentage should align with actual voltage, and the early shutdowns stop.