About this replacement
Asus VivoBook 16X K3605VC — 11.55V Li-Polymer Replacement Battery (0B200-04070000)
This 11.55V, 4300mAh (49.67Wh) lithium-polymer cell replaces the original battery in the Asus VivoBook 16X K3605VC and its variants. It fits the K3605VC-AS96, K3605VC-N1004W, K3605VC-N1059W, and more than 60 additional K3605VC configurations. OEM part numbers covered: 0B200-04070000 and C31N2024.
- K3605VC platform compatibility: All K3605VC variants share the same voltage rail, physical connector, and BMS handshake protocol. The 11.55V three-cell configuration is consistent across the entire production run, so one cell SKU covers the full range.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the K3605VC platform. The BMS communicated correctly with the EC, reported accurate state-of-charge readings, and held voltage within spec across the full capacity range without triggering a protection cutoff.
- Post-install calibration for the K3605VC: After fitting this cell, run the laptop down to hibernate cutoff under normal load — open applications, active display — then charge uninterrupted to 100%. This forces the BIOS battery learn cycle to reset against the new cell's actual capacity curve and clears the inaccurate health warning that appears after every cell swap on this platform.
BIOS reporting poor battery health immediately after fitting a new K3605VC cell
The K3605VC EC reads health data from EEPROM registers that carry over from the previous cell. When a new cell goes in, the BIOS compares the new cell's open-circuit voltage against stored cycle count and capacity data from the old pack — and flags a mismatch as degraded health. This is a calibration state, not a hardware fault. One full discharge-to-hibernate followed by an uninterrupted charge to 100% rewrites the learn cycle data. After two to three full cycles, the health readout normalises and the warning clears.
VivoBook 16X shutting down at 20–30% charge shown on screen
This happens when the cell voltage drops below the EC's cutoff threshold before the fuel gauge reaches zero — a voltage cliff under combined CPU and display load. The fuel gauge IC was calibrated to the old cell's discharge curve, so its percentage estimate is ahead of actual voltage. Running one complete discharge cycle to hibernate lets the gauge IC relearn the new cell's voltage-to-capacity relationship. After that cycle, the reported percentage and the actual cutoff voltage align — target a resting voltage of 11.1V or above at the 20% mark as confirmation the recalibration worked.