NBL-42A2200 Neffos C5 Replacement Battery 3.8V 1700mAh

Neffos C5 / C5 LTE Dual SIM — 3.8V Li-ion Replacement Battery (NBL-42A2200)

This is a 3.8V Li-ion cell rated at 1700mAh (6.46Wh), built to fit the Neffos C5, C5 LTE Dual SIM, and TP701A smartphones. It slots into the same battery bay as the original NBL-42A2200 and NBL-42A2280 units. Swap it in when the existing cell no longer holds a charge or causes unexpected shutdowns.

• C5 and TP701A platform compatibility: These three models share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The 100.52 × 42.00 × 4.20mm cell fits all three without modification to the housing or flex cable routing.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the C5 platform. The BMS accepted the charge IC handshake without fault flags, and cell voltage held steady at 3.8V nominal through the discharge curve.
• Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging and run one complete discharge-charge cycle. This gives the fuel gauge IC time to map the new cell's discharge curve before high-current charging begins on an uncalibrated cell.

Sudden shutdown at 20–30% on the Neffos C5 after a cell swap

This is a voltage cliff issue, not a defective cell. The Neffos C5's charge IC and modem draw short high-current bursts — particularly during LTE handoffs and screen-on events. A new cell with an uncalibrated fuel gauge IC can report 25% remaining while actual cell voltage drops below the BMS cutoff threshold under load. The phone shuts down to protect the cell even though the percentage display says otherwise. One full discharge-charge cycle at standard charge current resets the coulomb counter and resolves the mismatch.

Phone shows erratic or jumping battery percentage after replacement

The fuel gauge IC in the C5 stores a learned discharge curve from the old cell. After a cell swap, that stored curve no longer matches the new cell's actual voltage-to-capacity relationship, so the percentage reading jumps. This is not a sign of a faulty battery. Drain the phone fully until it powers off, then charge uninterrupted to 100% — that single cycle lets the IC relearn the curve. After that first full cycle, percentage readings stabilise and track correctly.