LG Optimus F6 BL-59JH Replacement Battery 3.7V 1650mAh

LG Optimus F6 / MS500 / D500 — 3.7V Li-ion Replacement Battery (BL-59JH)

This is a 3.7V, 1650mAh Li-ion cell built to fit the LG Optimus F6 and its carrier variants — the MS500, D500, and D505. It replaces OEM part numbers BL-59JH, EAC61998401, EAC61998402, and EAC62018401. If your original cell no longer holds a charge or the phone shuts down unexpectedly, this is the direct swap.

• F6 / MS500 / D500 / D505 platform fit: These four models share the same battery bay dimensions, connector pinout, and BMS handshake protocol — one cell covers all of them without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on an F6 unit. The BMS accepted the cell without error flags, thermal cutoff held within normal range, and the charge IC brought it to full without interruption.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before the charge IC begins pushing higher current into an uncalibrated cell.

Why the Optimus F6 reports wrong battery percentage after a cell swap

The Optimus F6 uses a coulomb counter in its fuel gauge IC that builds a model of the cell's charge curve over time. When you install a new cell, that model is still calibrated to the old, degraded cell. The phone reads voltage from the new cell and maps it against the wrong curve, so the percentage display is inaccurate — often reading high and then dropping suddenly. One full discharge to shutdown followed by a full charge at standard rate resets the coulomb counter to the new cell's actual curve. After that cycle, percentage readings stabilise.

Sudden shutdown at 20–30% on the replacement cell

This happens when the modem or display draws a current spike the cell cannot sustain without the voltage dropping below the BMS cutoff threshold — typically around 3.0V per cell. It is not a capacity defect; it is the fuel gauge IC misreporting the remaining charge because it has not yet completed a calibration cycle. Run one full discharge from 100% to automatic shutdown, then charge uninterrupted to 100% at standard rate. If shutdowns continue past two calibration cycles, check that the battery connector is fully seated — a loose pin creates resistance that amplifies voltage sag under load.