About this replacement
Asus VivoBook E200HA — 7.6V Li-Polymer Replacement Battery (C21N1521)
This is a 7.6V, 3350mAh (25.46Wh) Li-Polymer replacement battery for the Asus VivoBook E200HA series. It replaces OEM part numbers C21N1521 and 0B200-01870000. It fits the VivoBook E200HA, E200HA-1A, E200HA-1B, E200HA-1E, and over 57 additional VivoBook E200HA variants.
- VivoBook E200HA series compatibility: All E200HA variants share the same two-cell Li-Polymer configuration, voltage rail, and board connector. The BMS handshake is standardised across the range, so the same cell fits every suffix variant without modification.
- Bench tested on actual hardware: We ran this cell through a full charge and discharge cycle on a VivoBook E200HA board. The BMS accepted the cell immediately, charge regulation kicked in at the correct voltage threshold, and the protection circuit tripped cleanly at the low-voltage cutoff.
- First-cycle recalibration on the E200HA: After fitting, run the laptop down until it hibernates on low battery, then charge uninterrupted to 100% without unplugging. This forces the E200HA's BIOS battery learn cycle to reset against the new cell and clears the inaccurate health warning that appears after every cell swap.
BIOS reporting poor battery health immediately after fitting the C21N1521
The E200HA reads battery health data from EEPROM registers carried over from the old cell. When a new cell goes in, those registers still hold the degraded values from the previous battery. The BIOS flags this as poor health before it has run a single learn cycle. One full discharge-to-hibernate followed by an uninterrupted charge to 100% rewrites the learn data and clears the warning. After that cycle, the health indicator should read normal.
E200HA shuts down at 20–30% battery remaining shown on screen
This is a voltage cliff, not a capacity fault. Under combined CPU and display load, the cell voltage drops faster than the fuel gauge IC can track. When voltage hits the protection cutoff, the system shuts down even though the gauge still shows charge remaining. The fuel gauge IC needs two to three full calibration cycles against the new cell before its readings align with actual cell voltage. Run the laptop through full discharges to hibernate and full recharges each time — the shutdowns should stop by the third cycle.