About this replacement
Acer Predator Triton 500 PT515-51-76VM — 15.2V Li-Polymer Replacement Battery (AP18JHQ)
This is a 15.2V, 5400mAh (82.08Wh) Li-Polymer battery for the Acer Predator Triton 500 PT515-51-76VM gaming laptop. It also fits the ConceptD 7 CN715-71 series and over 140 additional Acer models sharing the same cell format and connector. OEM part numbers AP18JHQ and KT.00408.001 both cross to this cell.
- Triton 500 and ConceptD 7 platform compatibility: These models share the same 15.2V four-cell Li-Polymer architecture, connector pinout, and BMS handshake protocol. The charge controller on each expects the same impedance signature and EEPROM data structure, which is why one cell covers both product lines.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a PT515-51 board. The BMS handshake completed without fault codes, charge acceptance held steady across cycles, and the BIOS read capacity within expected tolerance after a full learn cycle.
- Post-install calibration for the Triton 500: After fitting, run the laptop on battery until it hibernates at low charge, then charge uninterrupted to 100% without interruption. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap.
BIOS reporting poor battery health immediately after fitting a new cell
The Triton 500 BIOS stores battery health data in EEPROM on the old cell. When a new cell goes in, the BIOS compares the new cell's reported charge state against the stored baseline and flags a mismatch as poor health. This is not a fault with the replacement cell — it is a calibration state. Running one full discharge-to-hibernate cycle followed by an uninterrupted charge to 100% forces the BIOS to rewrite the learn table against the new cell. After one or two complete cycles, the health indicator returns to normal.
Laptop shuts down at 20–30% charge shown on screen
Under full gaming load — CPU boost, GPU draw, and display at full brightness simultaneously — total system draw on the Triton 500 can exceed 80W from the battery alone. A degraded or uncalibrated cell hits a voltage cliff before the fuel gauge reaches zero, and the BMS trips the circuit to protect the cells. The OS reads the state-of-charge as 20–30% because the fuel gauge IC has not yet mapped the new cell's actual discharge curve. Run two full calibration cycles and confirm the cell voltage at shutdown reads above 14.4V total pack — if it is cutting off below that, the BMS is responding to a real voltage drop, not a gauge error.