About this replacement
Asus Chromebook C300 Series — 11.4V Li-Polymer Replacement Battery (B31N1346)
This is an 11.4V, 4200mAh (47.88Wh) Li-Polymer replacement battery for the Asus Chromebook C300, C300M, C300MA, and C300MA-DB01 series. It replaces OEM part numbers B31N1346 and 0B200-01010000. Fits the three-cell battery bay on C300MA boards without modification.
- C300 series compatibility: The C300, C300M, and C300MA all share the same three-cell 11.4V architecture and use the same connector pinout and BMS handshake protocol. One cell fits the full model range.
- Bench tested on actual hardware: We ran this cell on a C300MA board. The BMS accepted the cell, charge negotiation started within 30 seconds, and the protection circuit responded correctly to both over-voltage and over-current triggers during the test cycle.
- First-cycle reset on C300MA: After installation, run one full discharge to hibernate cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle on ChromeOS and clears the inaccurate health warning that appears after every cell swap on this platform.
BIOS reporting poor battery health immediately after installation on C300MA
The C300MA BIOS reads health data from the EEPROM on the old cell. When you swap the battery, the BIOS compares the new cell's charge data against stored values from the previous cell and flags a mismatch as degraded health. This is a firmware calibration issue, not a fault with the replacement cell. Running one complete discharge-to-hibernate then a full uninterrupted charge allows ChromeOS to rewrite the battery learn cycle data. After two to three full cycles, the health indicator stabilises.
Chromebook C300 shutting down at 20–30% charge shown on screen
This happens when the fuel gauge IC has not yet calibrated against the new cell's actual voltage curve. The gauge was trained on the old, degraded cell, so it reads the new cell's voltage curve incorrectly and triggers shutdown before the cell is actually depleted. The fix is the same learn cycle: discharge fully to hibernate cutoff, then charge to 100% without interruption. Repeat this two to three times and the fuel gauge IC re-maps to the new cell — shutdowns at false low percentages stop.