Li3826T43P4H705949 ZTE Avid 579 Compatible Battery 3.8V 2100mAh

ZTE Avid 579 / Blade A530 — 3.8V Li-ion Replacement Battery (Li3826T43P4H705949)

This is a 3.8V, 2100mAh Li-ion cell built to the same spec as the original ZTE Li3826T43P4H705949. It fits the ZTE Avid 579, BA530, BA606, and Blade A530 series phones. Voltage and form factor match the OEM cell at 69.70 × 58.94 × 4.60mm.

• Avid 579, BA530, BA606, Blade A530 compatibility: These models share the same 3.8V battery rail, connector pinout, and BMS handshake protocol. One cell fits all of them because ZTE used a common power platform across this budget device line.
• Bench tested on actual hardware: We ran this cell through full charge-discharge cycles and confirmed the BMS communicates charge state correctly to the OS. The protection circuit tripped at expected low-voltage cutoff with no false shutdowns above 3.2V.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes into an uncalibrated coulomb counter.

Sudden shutdown at 20–30% on the Avid 579

This happens when the cell voltage drops sharply under load from the modem or display — even though the reported percentage still looks safe. The fuel gauge IC is predicting remaining charge from a curve it built on the old, degraded cell. A fresh cell has a steeper voltage cliff at the low end until it gets recalibrated. Run one full drain to auto-shutdown followed by a full charge to 100%, and the gauge will re-anchor its curve to the new cell's actual discharge profile.

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

Li-ion cells self-discharge during storage. If the cell has dropped below 2.5V, the BMS locks out to prevent damage — and the phone shows nothing when you press power. Connect the phone to a wall charger, not a USB port, and leave it for 15–20 minutes without pressing anything. The charge IC needs to push a trickle current through the BMS lockout threshold before normal charging can resume. If the screen still shows no charging indicator after 20 minutes, try a second wall adapter — some low-output chargers cannot source enough current to wake a locked BMS at this voltage.