About this replacement
Asus ZenPad 3S 10 LTE / Z500KL — 3.85V Li-Polymer Replacement Battery (C12P1602)
This is a 3.85V, 7700mAh (29.65Wh) lithium-polymer battery for the Asus ZenPad 3S 10 LTE and Z500KL tablets. It also fits the ZenPad Z10 and ZT500KL. OEM part numbers C12P1602 and 0B200-02110100 both reference this same cell.
- Z500KL and ZT500KL platform compatibility: These models share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The fuel gauge IC communicates over the same I²C bus, so the replacement cell is recognised without flashing or pairing procedures.
- Bench tested on actual hardware: We ran this cell on a Z500KL unit and confirmed the BMS accepted the new pack at first connection, charge current ramped normally through constant-current phase, and the charge IC transitioned to trickle correctly at 4.35V.
- Fuel gauge IC reset after installation: After fitting this battery, run one full discharge to automatic shutoff, then charge uninterrupted to 100% without using the tablet. This resets the fuel gauge IC calibration against the new cell and clears the inaccurate percentage readings that almost always appear directly after a swap.
Why the ZenPad Z500KL shuts down at 15–25% remaining
The Z500KL drives a 2048×1536 display and simultaneous LTE or Wi-Fi, which pulls a combined load high enough to cause a sharp voltage drop at the cell level. When cell voltage dips below the BMS cutoff threshold under that load, the tablet shuts off even though the fuel gauge still shows charge remaining. A degraded original cell with elevated internal resistance hits that voltage cliff much earlier in the discharge curve. The replacement cell's lower internal resistance flattens the discharge curve and pushes that cutoff point much closer to true empty — but only after one full calibration cycle.
Fast charging not available after battery swap on the ZenPad 3S 10
The ZenPad 3S 10 uses a proprietary charge negotiation sequence over the USB-C port that must complete at least one full accepted charge cycle before the charge IC unlocks higher current rates. Immediately after a swap, the device defaults to standard 5V charging as a safety measure while the BMS and charge controller synchronise state on the new cell. Connect the original Asus charger — third-party USB-PD adapters often fail the handshake — and allow one uninterrupted full charge from near-empty to 100%. Fast charge should then become available on the next charge session.