LG Optimus F6 Replacement Battery BL-59JH 3.8V 2300mAh

LG Optimus F6 / D500 Series — 3.8V Li-ion Replacement Battery (BL-59JH)

This is a 3.8V, 2300mAh Li-ion battery for the LG Optimus F6, MS500, D500, and D505 smartphones. It slots into the same battery bay as the original BL-59JH and uses the same three-contact connector. Dimensions are 64.96 × 43.92 × 5.92mm — confirm yours before ordering if the phone has been repaired before.

• F6 / D500 / D505 platform fit: These models share the same battery bay geometry, contact layout, and BMS handshake protocol. The fuel gauge IC on each reads the same discharge curve parameters, so one cell covers all variants without firmware conflicts.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on an F6 unit. The BMS accepted the charge handshake on the first cycle, and the protection circuit tripped correctly at the low-voltage cutoff threshold without requiring a manual reset.
• Fuel gauge recalibration on first use: After fitting this cell, disable any fast or adaptive charging and run one full discharge down to automatic shutdown, then charge uninterrupted to 100%. The F6's fuel gauge IC maps its coulomb counter to the new cell's discharge curve during this first cycle — skipping it causes erratic percentage readings for days.

Sudden shutdown at 20–30% on the Optimus F6

The F6's Snapdragon 400 SoC and LTE modem draw current in sharp bursts during active calls or data transfers. If the cell's internal impedance is high — common in aged or deeply discharged cells — terminal voltage drops below the BMS cutoff threshold under load even when the fuel gauge still shows charge remaining. The phone shuts off because the BMS is responding to an instantaneous voltage collapse, not an actual empty cell. Replacing the cell reduces impedance, and the shutdowns stop once the fuel gauge IC recalibrates through one full discharge-charge cycle. After replacement, confirm the phone holds voltage above 3.4V under screen-on load.

Phone won't power on after the replacement cell sat in storage

Li-ion cells in storage self-discharge at roughly 2–3% per month. If this battery sat unused long enough, cell voltage may have dropped below 2.5V — the threshold where the BMS enters lockout to prevent damage. The phone won't respond to the power button and may show no charging indicator for the first several minutes. Connect to a wall charger, not a USB port, and leave it for 15–20 minutes before pressing power. Wall adapters supply enough current to wake the BMS; most USB ports cannot. Once the BMS resets, the phone boots normally and the charge IC takes over.