About this replacement
Compaq Evo N410 Series — 14.8V Li-ion Replacement Battery (291694-001)
This is a 14.8V, 2200mAh Li-ion battery for the Compaq Evo N410, Evo N400C, Evo N410c, and Presario 305 series notebook computers. It replaces OEM part number 291694-001. These are early-2000s business laptops still in active use where the original cells have long since degraded below usable capacity.
- Evo N410 and N400C series compatibility: These models share the same 14.8V battery rail, connector pinout, and BMS handshake protocol — which is why a single cell works across the N410, N400C, N410c, and Presario 305 variants despite slight chassis differences.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on Evo N410 hardware. The BMS negotiated correctly with the system board, charge current tapered normally at full capacity, and no fault flags were triggered during load testing.
- Post-install discharge cycle on Evo N410: After fitting this battery, 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.
BIOS reporting battery health as poor immediately after swap on Evo N410
The Evo N410 BIOS reads health data stored in the outgoing cell's EEPROM and compares it against the new cell's reported state. A fresh cell with no charge history registers as anomalous to the firmware, which flags it as degraded or unknown. This is a firmware interpretation issue, not a fault with the replacement cell. One full discharge-to-hibernate followed by an uninterrupted charge to 100% writes new baseline data and clears the warning on the next POST.
Laptop shuts down abruptly at 20–30% charge shown on screen
This happens when the cell voltage drops below the BMS cutoff threshold under combined CPU and display load, even though the fuel gauge still reads 20–30%. The fuel gauge IC on this platform calibrates its percentage estimate against the old cell's discharge curve — it doesn't immediately know the new cell's actual voltage floor. The result is a percentage reading that outruns real capacity under load. Run two full discharge-to-recharge cycles and the fuel gauge IC will recalibrate against the new cell's actual curve, typically bringing shutdown to below 5% shown.