Asus Memo Pad 8 Compatible Battery C11P1329 3.8V 3900mAh

Asus Memo Pad 8 ME181C / ME181A — 3.8V Li-Polymer Replacement Battery (C11P1329)

This 3.8V, 3900mAh Li-Polymer battery replaces part number C11P1329 in the Asus Memo Pad 8 tablet lineup. It fits the ME181C, ME181A, and AST21 variants, along with 22 additional Memo Pad 8 configurations sharing the same cell format. Dimensions are 101.00 x 98.10 x 2.80 mm — confirm clearance before ordering if your unit has been repaired previously.

• ME181C and ME181A platform fit: These models share a common PCB layout, connector pinout, and battery bay depth. The BMS handshake runs over the same three-pin configuration across the entire ME181 series, so one cell spec covers all variants listed.
• Bench tested on actual hardware: We ran this cell on a ME181C unit and monitored the charge IC through a full cycle. The BMS accepted the new cell without error flags, and the protection circuit tripped correctly at both high-voltage cutoff and low-voltage floor.
• Fuel gauge recalibration after swap: After fitting this battery, run the tablet down to automatic shutoff from a full charge — do not manually power it off. Then charge uninterrupted to 100%. This gives the fuel gauge IC a fixed reference point against the new cell and clears the inaccurate percentage readings that appear immediately post-swap.

Tablet shutting down at 15–25% remaining after battery replacement

The Memo Pad 8 draws simultaneously from the display backlight and Wi-Fi radio under normal use. That combined load creates a brief voltage sag that the fuel gauge — still calibrated to the old, degraded cell — misreads as a critically low state of charge. The tablet's firmware triggers a protection shutdown before the actual cell voltage reaches cutoff. One full discharge-to-shutoff cycle followed by an uninterrupted charge to 100% resets the fuel gauge's discharge curve against the new cell and eliminates the premature cutoff.

Fast charging not available after fitting a new C11P1329 cell

The Memo Pad 8 uses a proprietary charge negotiation step between the charge IC and the battery's BMS. On a freshly installed cell, the charge IC defaults to a conservative current limit until it completes one accepted full charge cycle. Charging at the lower rate on the first cycle is normal behaviour, not a fault. Use the original Asus adapter for that first cycle — third-party adapters that don't assert the correct voltage handshake can leave the IC in slow-charge mode permanently.