ZOPO ZP580 Compatible Battery BT33S 3.7V 2000mAh Li-ion

ZOPO ZP580 / 6580 — 3.7V Li-ion Replacement Battery (BT33S)

This is a 3.7V, 2000mAh Li-ion replacement cell for the ZOPO ZP580 and 6580 smartphones. It slots into the same battery bay as the original BT33S unit. At 7.4Wh, it matches the factory specification for these handsets.

• ZP580 and 6580 compatibility: Both models use the same BT33S battery format — identical connector pinout, cell dimensions (69.27 × 59.95 × 4.20 mm), and 3.7V nominal rail. The BMS on each handset uses the same charge termination threshold, so one cell fits both without modification.
• Bench tested on actual hardware: We ran this cell through the ZOPO charge IC handshake on the bench. The BMS accepted the charge cycle without tripping protection, and the coulomb counter registered capacity within normal tolerance of the rated 2000mAh across a full discharge profile.
• Fuel gauge recalibration on first use: After installation, disable any fast-charge mode and run one complete discharge-to-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before fast current is applied to an uncalibrated cell — otherwise percentage readings will drift from the first charge onward.

Sudden shutdown at 20–30% on the ZP580 after a cell swap

This is a voltage cliff issue. Under high-draw conditions — active screen, LTE modem, and background sync running simultaneously — the new cell's internal impedance causes voltage to sag below the BMS cutoff threshold before the percentage gauge hits zero. The fuel gauge IC is still reading state-of-charge from a curve calibrated to the old, degraded cell. One full discharge cycle from 100% down to automatic shutoff, followed by an uninterrupted charge to 100%, resets the coulomb counter against the new cell's actual curve.

ZP580 not powering on after the replacement battery sat in storage

Li-ion cells self-discharge during storage. If the cell voltage has dropped below approximately 2.5V, the BMS enters lockout to prevent damage and will refuse a normal charge. The phone shows nothing when connected to a charger. Connect the handset to a low-current USB source — a standard 5V/500mA port, not a fast charger — and leave it for 20–30 minutes without pressing the power button. This allows the charge IC to trickle current into the cell until it clears the BMS recovery threshold, typically around 3.0V, at which point normal charging resumes.