Lenovo ZUK Z5 BL288 Replacement Battery 3.85V 3050mAh

Lenovo Zuk Z5 — 3.85V Li-Polymer Replacement Battery (BL288)

This is a 3050mAh (11.74Wh) Li-Polymer cell at 3.85V, built to replace the OEM BL288 in the Zuk Z5 smartphone. It fits the L78011 and L78012 variants directly. If your Z5 shuts down unexpectedly, won't hold charge, or has swollen in the chassis, this cell replaces the original without hardware modification.

• Zuk Z5, L78011, L78012 compatibility: All three share the same voltage rail, BL288 connector footprint, and BMS handshake protocol. One cell spec covers the full variant range without adapter or firmware workaround.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a Z5 unit, confirmed BMS communication at first boot, and verified charge IC acceptance without fault flags or thermal shutdown.
• Fuel gauge recalibration on first use: After fitting this cell, disable fast charging and run one full discharge-charge cycle at standard rate. This lets the fuel gauge IC map its coulomb counter to the new cell's discharge curve before high-current charging begins on an uncalibrated reference.

Sudden shutdown at 20–30% on the Zuk Z5 after a cell swap

This happens because the fuel gauge IC still holds the discharge curve from the degraded original cell. When the new cell hits a voltage point the old curve mapped to 20–30%, the IC signals empty and the OS cuts power — even though actual cell capacity remains. The fix is a full discharge to automatic shutdown, then a continuous charge to 100% without interruption. After one complete cycle, the coulomb counter resets against the new cell's real curve and percentage reporting stabilises.

USB fast charge not activating on first cycle after replacement

On the first connection after a BL288 swap, the charge IC may not negotiate the fast-charge protocol if the new BMS hasn't completed its initial handshake cycle. The phone charges slowly or shows standard 5W input despite being on a fast-charge adapter. Disconnect the cable, power cycle the phone fully, then reconnect to the charger. Once the BMS completes its initialisation sequence, fast-charge negotiation resumes normally — confirm by checking the charging indicator icon updates to the fast-charge symbol.