About this replacement
Acer TravelMate P2 TMP215-41-R74Q — 15.4V Li-Polymer Replacement Battery (AP19B5L)
This is a 15.4V, 3500mAh (53.9Wh) lithium-polymer battery for the Acer TravelMate P2 TMP215-41-R74Q and a broad range of compatible Acer laptops including the Enduro Urban N3 EUN314-51W and Swift 3 SF314-512 series. It replaces OEM part numbers AP19B5L and KT00405010. Install it when the original cell no longer holds a useful charge or the system shuts down unexpectedly under load.
- TravelMate P2 and Swift 3 platform fit: These Acer models share a common 15.4V four-cell Li-Polymer architecture, identical connector pinout, and the same BMS communication protocol over the SMBus line — that is why one part number covers all of them.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a TMP215-series unit. The BMS handshake completed on first connect, the BIOS recognised the pack without flagging an unknown device, and the protection circuit responded correctly at both low-voltage cutoff and thermal limits.
- Post-swap calibration on the TravelMate P2: After fitting this battery, run the laptop down to hibernate cutoff on battery power only — no AC — then charge uninterrupted to 100%. This forces the BIOS battery learn cycle to reset against the new cell and clears the inaccurate health warning that appears after every cell swap on this platform.
Why the TravelMate P2 shuts down at 20–30% after a battery swap
The fuel gauge IC on this platform stores a learned voltage-to-capacity curve from the previous cell. When a new cell goes in, that stored curve no longer matches the actual discharge profile of the new chemistry. Under full CPU plus display load, voltage drops faster than the old curve predicts, and the system hits its emergency cutoff before the gauge reaches zero. Running two to three full discharge-to-hibernate cycles recalibrates the IC against the new cell. After calibration, the cutoff point will track correctly — expect it to align at or below 5% remaining.
BIOS reporting 0% or "unknown battery" immediately after fitting
This happens because the EEPROM data broadcast by the new cell does not match what the BIOS cached from the old pack. The system flags the pack as unknown rather than reading it as degraded. Power the laptop fully off, reseat the battery connector firmly, then boot into BIOS setup and navigate to the battery health or power section — this forces a fresh SMBus query. If the BIOS still shows 0%, a single full charge cycle from flat typically resets the fuel gauge register to a valid state.