About this replacement
Asus ZenPad 8.0 Z380C Series — 3.8V Li-Polymer Replacement Battery (C11P1505)
This is a 3.8V, 3900mAh Li-Polymer battery for the Asus ZenPad 8.0 tablet range. It fits the Z380C, Z380CX, Z380KL, and P022 variants. Capacity figure comes from the product specification — 14.82Wh total energy.
- Z380 series compatibility: The Z380C, Z380CX, and Z380KL share the same battery bay dimensions and connector pinout. All three models use the same BMS handshake voltage threshold, so one cell works across the range without modification.
- Bench tested on actual hardware: We ran the C11P1505 replacement through charge-discharge cycles on the Z380C. The BMS accepted the cell on first connect, charge IC engaged correctly, and voltage held stable across the display and Wi-Fi load combined.
- Fuel gauge recalibration after swap: After fitting this battery, run the tablet down to automatic shutoff, then charge it uninterrupted to 100% without interruption. This forces the fuel gauge IC to recalibrate against the new cell and clears the inaccurate percentage readings that commonly appear after a battery replacement.
ZenPad 8.0 shutting down at 15–25% remaining
This happens when the fuel gauge IC still holds calibration data from the old, degraded cell. The tablet hits a voltage cliff under combined display and Wi-Fi draw before the reported percentage reaches zero. The device interprets this voltage drop as an empty battery and shuts down. Run one full discharge cycle to automatic shutoff, then charge to 100% — the gauge resets and the early shutdowns stop.
Fast charging unavailable after battery replacement on Z380KL
The Z380KL uses USB-PD negotiation to enable higher charge rates. After a battery swap, the charge controller requires one complete accepted charge cycle before it re-enables the higher voltage contract with the charger. On the first charge post-install, use the original Asus adapter. Once that first full cycle completes, fast charging becomes available again as normal.