About this replacement
ZTE Prestige 2 / N9136 — 3.7V Li-ion Replacement Battery (Li3820T43P4H694848)
This is a 3.7V, 1750mAh Li-ion replacement battery for the ZTE N9136, Prestige 2, Prestige 2 TD-LTE, and Z835. It matches the OEM part number Li3820T43P4H694848 and fits the same physical bay. At 68.82 x 48.34 x 5.18mm, it drops into the factory compartment without modification.
- N9136 / Prestige 2 platform fit: These models share the same battery bay dimensions, connector pinout, and BMS communication protocol — one cell covers all listed variants without adapter or firmware workaround.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the N9136 platform. The BMS handshake completed on the first cycle, thermal limits engaged correctly under screen-on load, and the charge IC accepted standard current without flagging an error.
- Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-charge cycle before re-enabling it. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes into an uncalibrated state.
Why the N9136 reports wrong battery percentage after a cell swap
The ZTE N9136 uses a coulomb-counter fuel gauge IC that builds its reference curve against the original cell over hundreds of cycles. When you swap in a new cell, the IC is still running the old calibration table. It will report incorrect state-of-charge — often reading high, then dropping suddenly. One full discharge to shutdown followed by an uninterrupted charge to 100% resets the counter reference. After that single cycle, percentage readings stabilise against the new cell's actual curve.
Sudden shutdown at 20–30% on the replacement cell
This is a voltage cliff issue, not a capacity fault. Under modem transmit or screen-on load, the new cell briefly drops below the BMS cutoff threshold even though the fuel gauge still shows charge remaining. It happens most often in the first few cycles before the cell's internal resistance settles. Run two full discharge-charge cycles without fast charging — cell impedance drops as the lithium intercalation layers stabilise, and the voltage sag under load narrows. If shutdown still occurs at or above 25%, check that the connector is fully seated; a loose pin raises contact resistance and amplifies the voltage sag.