About this replacement
ZTE Axon 7 mini — 3.85V Li-Polymer Replacement Battery (Li3927T44P8h726044)
This 3.85V, 2700mAh Li-Polymer battery replaces the original cell in the ZTE Axon 7 mini, Axon 7 Mini Dual, and B2017G. It matches the OEM part number Li3927T44P8h726044 and fits the same 71.20 x 59.90 x 4.20mm bay. Capacity rating comes direct from product data — 10.4Wh nominal.
- Axon 7 mini / B2017G platform fit: The Axon 7 mini, Axon 7 Mini Dual, and B2017G share the same battery bay dimensions, connector pinout, and BMS handshake protocol — one cell covers all three variants without modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the Axon 7 mini platform. The BMS accepted the cell without fault codes, and the charge IC negotiated current correctly through a full cycle.
- Fuel gauge recalibration on first use: Disable fast charging for the first complete discharge-charge cycle after installation. The fuel gauge IC is calibrated to the old cell's discharge curve — running one full cycle at standard current lets it map the new cell before high-current charging begins.
Sudden shutdown at 20–30% after a cell swap on the Axon 7 mini
The Axon 7 mini's fuel gauge IC stores a discharge curve learned from the original cell. A new cell has different internal impedance, so the IC's voltage prediction is off — it reads 25% remaining but the cell voltage is already dropping below what the modem and display can sustain under load. The phone cuts power before the OS can warn you. One full discharge to automatic shutoff, followed by an uninterrupted charge to 100%, forces the coulomb counter to relearn the curve against the new cell. After that cycle, the reported percentage tracks actual cell state within normal tolerance.
USB fast charge not activating on the first cycle after replacement
On the first charge after installation, some units show the slow-charge indicator even when plugged into a fast-charge adapter. This happens because the charge IC checks cell voltage and impedance before enabling high-current mode — a new cell at low state of charge may fall outside the IC's acceptance window on that first handshake. Let the phone charge fully on a standard 5V/1A source for the first cycle. On the second charge with a fast-charge adapter, the IC re-negotiates from a known full-charge baseline and typically enables high-current mode at the correct threshold voltage.