About this replacement
ZTE Q701C / N968 Series — 3.8V Li-ion Replacement Battery (Li3720T42P3h816342)
This is a 3.8V, 2230mAh Li-ion cell for the ZTE Q701C, N968, Q508, and Q508U smartphones. It replaces OEM part numbers Li3720T42P3h816342 and Li3823T43P3h816342. Fit the replacement when the original cell no longer holds charge or the phone shuts down unexpectedly under load.
- Q701C / N968 platform compatibility: These models share the same battery bay dimensions (81.00 × 62.98 × 4.20mm), connector pinout, and BMS handshake protocol, which is why a single cell covers the full range.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge on a ZTE N968 unit. The BMS accepted the cell without error flags, charge termination fired correctly at 4.35V, and the protection circuit tripped cleanly at the low-voltage cutoff.
- Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-charge cycle at standard current. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes into an uncalibrated state.
Sudden shutdown at 20–30% on the replacement cell
A new cell has a slightly different voltage-versus-capacity curve than the worn cell the fuel gauge IC was trained on. When the modem fires a high-current burst — during a call, LTE handoff, or screen-on event — the cell voltage sags below the hardware cutoff threshold before the OS reads 0%. The phone interprets this as a fault and shuts down even though the percentage display still shows charge. One full discharge-charge cycle after fitting the new cell retrains the coulomb counter and eliminates most premature shutoffs. If shutdowns persist past the second cycle, verify the replacement voltage is 3.8V and not a 3.7V cell substituted at lower capacity.
Phone warm near the battery during the first charge after fitting
A new cell arrives with higher internal impedance than a broken-in one. The charge IC compensates by holding a slightly elevated charge voltage, which generates more heat at the cell surface during the first few cycles. This is normal and typically drops off after two to three full cycles as impedance falls. If the device remains noticeably warm beyond the third cycle, check that the charge port pins are clean and that the charger output is within the 5V/1A or 5V/2A spec for this handset.