About this replacement
Acer TravelMate 5310-400508Mi — 14.8V Li-ion Replacement Battery (GRAPE34)
This is a 14.8V, 4400mAh (65.12Wh) Li-ion replacement battery for the Acer TravelMate 5310-400508Mi and a wide range of TravelMate 5520G, 5720, and 7520G laptops. It replaces failed or capacity-depleted original cells using OEM part numbers including GRAPE34, LC.BTP00.006, and BT.00807.013. Voltage, connector pinout, and BMS communication all match the original specification.
- TravelMate 5310 / 5520G / 5720 / 7520G compatibility: These models share the same 14.8V four-cell battery architecture, identical connector housing, and the same BMS handshake protocol — which is why one replacement cell covers the full platform range across those series.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on TravelMate hardware. The BMS negotiated correctly with the BIOS, reported state-of-charge without error flags, and held voltage across the full discharge curve without unexpected cutoff.
- First-install calibration on TravelMate laptops: After fitting this cell, run one full discharge to hibernate cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap on this platform.
Why the TravelMate BIOS flags a new battery as poor health immediately after swap
The TravelMate BIOS reads health data from the battery's EEPROM, not from live cell voltage. When a new cell arrives, its EEPROM counters start at zero and its rated Wh figure may differ slightly from what the BIOS expects — triggering a false poor-health flag. This is a data mismatch, not a faulty battery. Running one full discharge-to-hibernate followed by a complete uninterrupted charge gives the fuel gauge IC enough data to recalibrate and clears the BIOS warning on most TravelMate units.
TravelMate shutting down at 20–30% charge shown on the gauge
When a battery's cells age, they hit a voltage cliff under combined CPU and display load — the cell voltage drops below the BMS cutoff threshold before the fuel gauge reaches zero. The result looks like an early shutdown, but the gauge reading is wrong, not the hardware. After installing this replacement, the fuel gauge IC needs two to three full charge-discharge cycles to map the new cell's actual voltage curve. Until those calibration cycles complete, the percentage shown may be inaccurate — do not judge the cell by the first cycle reading.