About this replacement
Dell Inspiron 13 5301 / Vostro 14 5402 — 11.25V Li-Polymer Replacement Battery (C5KG6)
This is an 11.25V, 3450mAh (38.81Wh) Li-Polymer battery for the Dell Inspiron 13 5301 and Vostro 14 5402 ultrabook series. It replaces OEM parts C5KG6, CF5RH, and JK6Y6. If your original cell no longer holds charge or the laptop won't run unplugged, this cell restores full portable operation.
- Inspiron 5301 and Vostro 5402 shared platform: Both models sit on Dell's Tiger Lake ultrabook chassis, using the same 11.25V three-cell pack with an identical connector pinout and BMS handshake protocol — which is why a single part number covers the whole range.
- Bench tested on actual hardware: We ran this cell on a 5301 unit and confirmed the BMS negotiated correctly with Dell's EC firmware — charge acceptance started immediately and the fuel gauge reported accurate state-of-charge after two full cycles.
- Post-install calibration for the 5301: After fitting, run the laptop down until it hibernates on its own, then charge uninterrupted to 100% without using the machine. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap.
BIOS reporting battery health as poor immediately after replacement
Dell's embedded controller reads EEPROM data written by the original cell at the factory. When a new cell goes in, that EEPROM signature doesn't match the stored baseline, so the EC flags health as degraded even though the new cell is fresh. This is a firmware state issue, not a hardware fault. Running one full discharge-to-hibernate followed by an uninterrupted charge to 100% forces the EC to rewrite its learned parameters against the new cell. After two of these cycles, the health warning clears in both the BIOS and Dell Power Manager.
Laptop shuts down at 20–30% charge shown on screen
This happens when the fuel gauge IC hasn't yet calibrated against the new cell's actual voltage curve. Under combined CPU and display load, the real cell voltage drops faster than the uncalibrated gauge predicts — the EC sees the voltage floor and forces shutdown while the OS still shows 20–30% remaining. It is not a defective cell. Run two full discharge-to-hibernate cycles to let the fuel gauge IC map the new cell's discharge profile accurately. After calibration, shutdown should not occur above 5% remaining, and resting cell voltage at that point should measure approximately 10.8V.