Motorola T190 SNN5623A Replacement Battery 3.6V 550mAh

Motorola T190 / T191 — 3.6V Ni-MH Replacement Battery (SNN5623A)

This is a 3.6V, 550mAh Ni-MH replacement battery for the Motorola T190 and T191 two-way radios. It uses OEM part number SNN5623A and slots directly into the battery compartment of both models. If your radio is losing charge faster than it used to, or no longer powering on, this cell replaces the degraded original.

• T190 and T191 compatibility: Both models share the same battery bay, connector pinout, and voltage rail, so one cell fits either radio without modification.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on a T190 unit. The battery charged cleanly to 4.2V equivalent terminal voltage, held load without voltage collapse, and the radio powered on with no fault indication.
• Ni-MH conditioning after installation: Ni-MH cells in two-way radios benefit from a full discharge before the first recharge. Run the radio until it powers off on its own, then charge fully. This prevents partial-charge memory from reducing usable capacity on subsequent cycles.

Why the T190 powers off before the battery indicator hits empty

The T190 uses a simple voltage-threshold circuit to estimate remaining charge — it does not use a coulomb counter. When a Ni-MH cell ages, its internal resistance rises. Under transmit load, voltage sags below the cutoff threshold even though resting voltage still reads mid-range. The result is an abrupt shutdown that looks like a fault but is a normal low-voltage protection response. Replacing the cell eliminates this sag because fresh Ni-MH cells have significantly lower internal resistance, typically under 100mΩ at this capacity class.

Radio shows full bars then drops to dead within a short period of use

This is the classic symptom of a cell that has lost capacity but still charges to full terminal voltage. The T190's indicator reads voltage at rest, so a degraded cell looks full at 4.35V until you key the transmitter and draw current. At that point, voltage collapses and the radio shuts down. The fix is a full replacement cell, not a recharge. After fitting the new SNN5623A cell, run one complete discharge cycle before trusting the bar indicator.