Simplehuman ST1045 Compatible Battery 3.7V 800mAh Li-ion

Simplehuman ST1045 / ST1044 / ST1043 / ST1046 — 3.7V Li-ion Replacement Battery (ICR14500-ST)

This is a 3.7V, 800mAh Li-ion cell replacing the ICR14500-ST in Simplehuman automatic sensor trash cans. It fits the ST1043, ST1044, ST1045, and ST1046 models — all of which use the same 14500-format cell to power the motorized lid and infrared sensor. When the original cell degrades, the lid stops responding or moves sluggishly; this cell restores full operation.

• ST1043–ST1046 platform fit: These four models share the same motor driver circuit and 14500 battery bay. The lid motor and IR sensor both draw from the same single cell, so voltage and cell format must match exactly — a standard AA cell will not work here even though it fits physically.
• Bench tested on actual hardware: We ran this cell through the ST1045 lid cycle on the bench. The BMS accepted the cell without error, the sensor activated cleanly on approach, and the motor completed full open and close strokes without voltage sag tripping the protection circuit.
• Post-install sensor reset on Simplehuman lids: After fitting this cell, hold your hand over the sensor for three seconds until the lid cycles once — this step re-initialises the proximity threshold. Skipping it can leave the sensor over-sensitive and cause the lid to open without a clear trigger.

Why the ST1045 lid stops mid-stroke after a battery swap

The lid motor on the ST1045 pulls a short current spike at the start of each open cycle. If the replacement cell's internal resistance is too high, voltage drops below the motor driver's minimum threshold mid-stroke and the BMS cuts output. The lid stalls halfway, then resets. This is not a mechanical fault — it means the cell cannot sustain the peak draw. This ICR14500-ST cell is rated to handle the motor's start surge without tripping the protection circuit.

Lid opens on its own after fitting a new cell

Random activations after a battery swap usually mean the IR sensor is still running on its previous calibration baseline. The sensor stores an ambient reference point, and inserting a fresh cell resets power without resetting that reference — so any movement in the room can trigger a flush cycle. Power the unit completely off for 10 seconds, then back on. The sensor will re-sample its baseline and ghost activations should stop. If they continue, confirm cell polarity is correct — reversed polarity causes erratic sensor output before the BMS shuts down at approximately 2.5V.