Marantz RC9001 Replacement Battery 3.7V 2200mAh

Marantz RC9001 — 3.7V Li-ion Replacement Battery

This 3.7V 2200mAh Li-ion battery fits the Marantz RC9001 infrared remote control. The RC9001 is used to operate Marantz A/V receivers and amplifiers. When the original cell loses capacity or refuses to hold a charge, this is the direct replacement.

• RC9001 fit: The RC9001 uses a single rechargeable Li-ion cell rather than disposable AA or AAA batteries. This cell matches the 3.7V nominal voltage and physical 65.99 × 18.33 × 18.33mm footprint the remote's battery bay requires.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the bench. The protection circuit tripped correctly at low-voltage cutoff and accepted a full charge without thermal event or BMS lockout.
• Single-cell install note: The RC9001 runs one Li-ion cell, so there is no second cell to worry about. Before fitting, confirm the polarity markings inside the bay match the cell's positive and negative terminals — Li-ion cells installed backwards will not power the remote and can stress the protection circuit.

Why the RC9001 IR signal weakens before the battery is fully depleted

The RC9001's IR LED needs a minimum voltage to fire at full intensity. A Li-ion cell begins dropping below that threshold well before it reaches 0% charge. The remote still powers on and the display may still light up, but the IR burst is too weak to trigger the receiver across a normal room. At that point the cell reads around 3.5V or lower — replace it rather than trying to recover it with a top-up charge.

RC9001 shows no response at all after fitting the new battery

A new cell that produces zero response is almost always installed backwards. The positive terminal on this Li-ion cell must align with the positive marking inside the RC9001's battery compartment. Reversed polarity blocks the circuit entirely — the remote will not power on, and no button will register. Remove the cell, flip it 180 degrees, reseat it, and press any button to confirm operation.