BlackBerry Z30 BAT-50136-001 Replacement Battery 3.8V 2800mAh

BlackBerry Z30 / STA100 Series — 3.8V Li-Polymer Replacement Battery (BAT-50136-001)

This is a 3.8V, 2800mAh Li-Polymer cell replacing the original battery in the BlackBerry Z30 and Z30 LTE smartphones. It fits STA100-1, STA100-2, and related STR100 variants sharing the same battery bay and connector. Cross-references include BAT-50136-001, BAT-50136-002, BAT-50136-101, BAT-50136-003, and CUWV1.

• Z30 and STA100 platform fitment: These models share an identical battery bay dimensions (111.66 × 56.86 × 3.40mm), the same 3.8V nominal rail, and a compatible BMS handshake with the Z30's charge IC — allowing a direct cell swap without adapters or firmware changes.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the Z30 platform. The BMS accepted charge-current handshake without triggering protective cutoff, and the fuel gauge IC registered cell capacity correctly after one full discharge-charge pass.
• Fuel gauge recalibration on first use: On first installation, disable any fast-charge mode and run one complete discharge-to-charge cycle before normal use. This gives the Z30's fuel gauge IC time to map the new cell's discharge curve accurately before high-current charging pushes current into an uncalibrated cell.

Why the Z30 reports wrong battery percentage after a cell swap

The Z30 uses a coulomb-counting fuel gauge IC that stores a discharge model built from the old cell's internal resistance and capacity curve. When a new cell goes in, that stored model no longer matches the physical cell. The gauge reads voltage correctly but maps it to the wrong state-of-charge percentage. One full discharge to automatic shutdown followed by a full charge to 100% forces the IC to re-anchor its endpoints and recalculate the curve against the new cell. After that cycle, percentage reporting stabilises.

Sudden shutdown at 20–30% remaining on the replacement cell

This happens when the fuel gauge IC hasn't recalibrated yet and the cell voltage drops sharply under load from the modem or display backlight. The phone still shows 25% charge but actual cell voltage has already fallen below the BMS protection threshold — roughly 3.0V under load — triggering an immediate shutdown. It's not a faulty cell; it's an uncalibrated gauge reading a voltage cliff incorrectly. Run a full discharge cycle from 100% to automatic shutdown, then charge uninterrupted to 100%, and the shutdowns will stop.