Dell Inspiron 1564 Replacement Battery 11.1V 6600mAh

Dell Inspiron 1564 Series — 11.1V Li-ion Replacement Battery (312-1021)

This is an 11.1V, 6600mAh (73.26Wh) Li-ion replacement battery for the Dell Inspiron 1564, 1564D, 1564R, and I1564 notebooks. It slots into the standard battery bay and connects via the original latch-and-contact system. Cross-reference OEM part numbers include 312-1021, 5YRYV, JKVC5, NKDWV, FH4HR, and CW435, among others listed above.

• Inspiron 1564 platform fit: The 1564, 1564D, and 1564R share the same battery bay geometry, contact layout, and BMS communication protocol — one cell works across all three variants without modification.
• Bench tested on actual hardware: We ran this cell on a 1564 chassis and confirmed the BMS handshake completes on first insertion, charge current ramps normally to 8.25V per cell pair, and the SMBus reports a valid pack ID to the BIOS without error flags.
• First-cycle calibration on the Inspiron 1564: After installing, run one full discharge to the hibernate cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health or low-capacity warning that appears after every cell swap on this platform.

BIOS reporting poor battery health immediately after fitting a new cell

The Inspiron 1564 BIOS reads health data from EEPROM registers stored on the battery's fuel gauge IC. When a new cell ships, those registers reflect factory defaults — not data learned from the specific notebook. The BIOS compares the reported design capacity against its stored baseline and flags a mismatch as "poor health." Running one full discharge-to-hibernate then a full charge-to-100% lets the fuel gauge IC write calibrated data back to EEPROM and clears the flag on next boot.

Laptop shuts down hard at 20–30% shown on the gauge

This happens when the cell voltage drops below the BMS cutoff threshold under the combined load of the CPU and display — even though the fuel gauge still shows charge remaining. The gauge IC is reading stored state-of-charge data that no longer matches the cell's actual voltage curve. It is not a firmware fault or a defective cell; it means the fuel gauge needs calibration cycles against the new chemistry. Discharge fully to hibernate cutoff two or three times with the charger disconnected, then recharge to 100% each time — the reported shutdown percentage will stabilise above 5%.