About this replacement
Sony Ericsson Xperia Z1 — 3.8V Li-Polymer Replacement Battery (LIS1525ERPC)
This 3.8V, 3000mAh Li-Polymer battery replaces the original LIS1525ERPC cell in the Sony Ericsson Xperia Z1, Xperia Z1 LTE, L35H, and SO-01F. It delivers 11.4Wh capacity and fits the same connector and form factor as the factory cell. Dimensions are 85.08 × 64.46 × 4.87mm — confirm these against your existing battery before ordering.
- Xperia Z1 platform compatibility: The Z1, Z1 LTE, L35H, and SO-01F all share the same battery bay geometry, 3.8V rail, and connector pinout. The BMS handshake on each of these variants expects the same charge termination voltage, so one cell covers the whole platform without modification.
- Bench tested on actual hardware: We ran this cell in an Xperia Z1 and cycled it through charge and discharge while monitoring BMS cutoff behaviour. The protection circuit tripped correctly at the low-voltage threshold, and the charge IC accepted the cell without fault flags on the second full cycle.
- Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle at standard rate. This lets the fuel gauge IC build an accurate discharge curve against the new cell before high-current charging is introduced into an uncalibrated state.
Sudden shutdown at 20–30% on the Xperia Z1 after a cell swap
The Xperia Z1's fuel gauge IC stores a learned discharge curve from the original cell. When a new cell goes in, that old curve no longer maps accurately to actual cell voltage. Under modem or display load, the cell voltage drops faster than the IC predicts, and the phone hits its hardware cutoff before the reported percentage reaches zero. The fix is one full uninterrupted discharge from 100% to automatic shutdown, followed by a full charge — this forces the coulomb counter to resync against the new cell's actual characteristics. After that cycle, shutdowns at 20–30% typically stop.
Device not powering on after the replacement battery sat in storage
Li-Polymer cells self-discharge in storage, and if this battery shipped or sat unused for an extended period, cell voltage may have dropped below 2.5V per cell — the BMS lockout threshold. At that point, the phone will not power on and will show no charging indicator. Connect to a wall charger (not a PC USB port, which may not supply enough current to wake the BMS) and leave it for 20–30 minutes without attempting to power on. Once the cell recovers above approximately 3.0V, the BMS releases lockout and normal charging resumes.