About this replacement
Asus VivoBook K3605VU Series — 11.61V Li-Polymer Replacement Battery (0B200-04240000)
This 11.61V, 5500mAh (63.86Wh) Li-Polymer battery replaces the original cell in the Asus VivoBook K3605VU, K3605VV, K3605VV-BB74, K3605VV-ES96, and over 65 additional K3605-series variants. It uses OEM part numbers 0B200-04240000 and C31N2105-1. The physical dimensions match the original tray at 285.60 x 84.80 x 6.40mm.
- K3605 series compatibility: All covered models share the same three-cell Li-Polymer architecture, 11.61V nominal rail, and matching BMS connector pinout. The fuel gauge IC communicates over the same SMBus line across the entire K3605 lineup, so the EEPROM handshake is consistent.
- Bench tested on actual hardware: We cycled this cell through charge, full-load discharge, and BMS cutoff on K3605-series hardware. The BMS accepted the cell without fault codes, and the protection circuit tripped correctly at low-voltage cutoff without requiring a manual reset.
- Post-install calibration on K3605 hardware: After fitting this cell, run one full discharge until the laptop hibernates, then charge uninterrupted to 100%. This forces the BIOS battery learn cycle to reset against the new cell and clears the inaccurate health warning that appears after every cell swap on this platform.
BIOS reporting battery health as poor after replacing the K3605 cell
The K3605 BIOS stores learned capacity data in EEPROM from the previous cell. When a new cell goes in, that stored data no longer matches the actual chemistry, so the BIOS flags the battery as degraded or unknown before any calibration has run. This is not a fault with the replacement cell. Run one full discharge-to-hibernate cycle followed by an uninterrupted charge to 100%, and the learn cycle will rewrite the EEPROM values against the new cell. After one or two full cycles, the health status normalises.
Laptop shuts down at 20–30% shown on the K3605 fuel gauge
This happens when the fuel gauge IC is still calibrated to the worn-out original cell. The percentage shown is based on stale capacity data, so what the OS reports as 25% is actually close to true empty on the new cell's voltage curve. Under combined CPU and display load, the cell voltage drops faster than the uncalibrated gauge expects, triggering an emergency shutdown. Run two full discharge-to-hibernate then charge-to-100% cycles to align the fuel gauge IC to the new cell. After calibration, the shutdown threshold shifts back to the correct range — below 5% shown.