About this replacement
Asus Memo Pad 8 ME181C / ME581CL — 3.8V Li-Polymer Replacement Battery (C11P1330)
This is a 3.8V, 3500mAh Li-Polymer replacement battery for the Asus Memo Pad 8 tablet series. It fits the ME181C and ME581CL models, along with the AST21 and several additional variants sharing the same cell format. Voltage and capacity match the original C11P1330 specification exactly.
- ME181C and ME581CL compatibility: Both models use the same 3.8V single-cell Li-Polymer pack with identical connector pinout and BMS communication protocol. The charge IC on each board expects the same voltage curve, so the same cell services both variants without any modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on ME181C hardware. The BMS accepted the new cell without fault flags, charge termination triggered correctly at 4.35V, and the protection circuit responded normally to simulated over-discharge conditions.
- Fuel gauge recalibration after swap: After fitting this battery, run the tablet down to automatic shutoff under normal use — display on, WiFi active — then charge uninterrupted to 100%. This forces the fuel gauge IC to re-map its capacity estimate against the new cell and clears the inaccurate percentage readings that typically appear immediately after a battery swap.
Memo Pad 8 shutting down at 15–25% remaining after battery replacement
The Memo Pad 8 shuts down early because its fuel gauge IC is still calibrated to the old, degraded cell. The voltage curve of a fresh Li-Polymer cell drops steeply below 3.6V, and the fuel gauge interprets that drop as a near-empty state before the cell is actually depleted. Combined load from the display and active WiFi accelerates voltage sag at that threshold, triggering a protective shutdown. One full discharge-to-shutoff followed by an uninterrupted charge to 100% recalibrates the IC against the new cell's actual curve and eliminates the early cutoff.
Fast charging unavailable on the Memo Pad 8 after a battery swap
Some users find the tablet reverts to standard 5V charging after a battery replacement, even with the same charger that previously delivered faster rates. The charge IC needs at least one complete accepted charge cycle on the new cell before it re-negotiates the higher voltage profile with the charger. Plug in with the original or a compatible USB charger, let the tablet charge fully without interruption, then unplug and repeat — by the second cycle the charge IC typically restores the faster charge rate. If it does not, confirm the charger output meets the original spec of 5V/2A or higher.