About this replacement
Asus AiO PT2001 Series — 15V Li-Polymer Replacement Battery (C41N1337)
This 15V, 4400mAh (66Wh) Li-Polymer battery replaces the original C41N1337 cell in the Asus AiO PT2001 19.5" all-in-one computer, including PT2001-04, PT2002-C1, and related PT2002 variants. It fits the same connector and BMS interface as the factory unit. Install it when the original cell no longer holds charge or the system refuses to run off battery power.
- PT2001 and PT2002 series compatibility: These models share a common 15V power rail, the same 4-cell Li-Polymer pack geometry, and identical BMS handshake requirements — which is why one cell covers the full PT200x lineup without hardware modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the PT2001 platform. The BMS completed charge handshake correctly, cell balancing engaged at 14.8V, and the pack reached full charge without triggering protection cutoff.
- Post-install calibration on the PT2001: After fitting this cell, run the system down to hibernate cutoff, then charge uninterrupted to 100%. The PT2001 BIOS uses this cycle to relearn capacity against the new cell and clear the false low-health warning that appears after every cell swap.
BIOS reporting poor battery health immediately after fitting a new cell
The PT2001 stores historical cycle count and capacity data in EEPROM on the old cell. When a new cell goes in, the BIOS reads no matching history and flags health as poor or unknown. This is a firmware read issue, not a fault with the replacement cell. One complete discharge-to-hibernate followed by a full uninterrupted charge gives the BIOS enough data to update its health estimate. After that cycle, the health status in ASUS Battery Health Charging normalises.
PT2001 shutting down at 20–30% charge shown on screen
The fuel gauge IC calibrates its percentage readout against the old cell's voltage curve. A new cell has a slightly different discharge slope, so the IC underestimates remaining capacity and calls shutdown early. This is not a hardware fault — it corrects itself over two to three full charge-discharge cycles as the IC maps the new curve. Force the first cycle all the way to hibernate cutoff at the lowest BIOS threshold, then charge to exactly 100% before using the system again.