T-Mobile CLIQ Replacement Battery SNN5843 3.7V 1300mAh

T-Mobile CLIQ / MotoSmart — 3.7V Li-ion Replacement Battery (SNN5843)

This is a 3.7V, 1300mAh (4.81Wh) Li-ion cell for the T-Mobile CLIQ and MotoSmart smartphones. The CLIQ is a 2009 Android slider with a physical QWERTY keyboard — original batteries from this era have been through hundreds of charge cycles and most are well past usable capacity. This cell replaces OEM part numbers SNN5843, SNN5843A, and BP6X.

• CLIQ and MotoSmart cell compatibility: Both handsets share the same physical footprint and voltage rail at 3.7V nominal. The battery connector pinout and BMS communication protocol match across both models, so one cell covers the pair without modification.
• Bench tested on actual hardware: We ran the cell through charge and discharge cycles on the CLIQ platform. The BMS accepted charge handshake from the device's charge IC without fault flags, and the protection circuit tripped correctly at the low-voltage cutoff threshold.
• Fuel gauge recalibration on first cycle: After fitting this cell, disable any battery-saver mode and run one complete discharge down to automatic shutdown, then charge uninterrupted to 100%. The CLIQ's coulomb counter needs a full cycle against the new cell's actual discharge curve before percentage readings become accurate.

Why the CLIQ reports wrong battery percentage after a cell swap

The CLIQ uses a fuel gauge IC that tracks capacity by counting charge in and out of the cell — a coulomb counter. When you swap in a new cell, the IC still holds the discharge curve map from the old, degraded cell. The new cell has a steeper, healthier voltage curve, so the IC misreads state of charge and displays inflated or erratic percentages. One full discharge-charge cycle overwrites the reference curve with real data from the new cell, and readings stabilise from that point forward.

Sudden shutdown at 20–30% on the replacement cell

This happens when the modem or display pulls a brief high-current load and the cell's resting voltage drops sharply under that load — hitting the BMS undervoltage cutoff even though the percentage gauge shows capacity remaining. On a new cell this usually means the fuel gauge IC has not yet recalibrated and is reporting a state of charge higher than actual. Run the full recalibration cycle described above. If shutdowns persist after recalibration, check that the battery contacts on the phone are clean and making full metal-to-metal contact — oxidised contacts add resistance and amplify voltage sag under load.