The Minut AC Power Adapter kit hardwires your M3 sensor into a junction box for continuous 24/7 power. It is not designed for use with a standard wall outlet- the adapter connects via terminal block directly to the building's electrical wiring. It replaces the standard magnetic mounting plate with a larger bracket that houses the adapter and routes the cable cleanly, eliminating the need to ever remove the sensor for charging.

This adapter must be hardwired into a recessed junction box by a certified electrician. It is not intended for a standard wall socket or extension cable, and installation may be subject to local electrical regulations.

What's in the box

AC Power Adapter kit contents

AC Power Adapter 80–240V AC input via terminal block. 5V 500mA USB-A output. Dimensions: 35 × 37 × 23 mm.	Mounting bracket 108 mm diameter. Fits standard EU/US ceiling junction boxes or mounts direct-to-structure.
USB cable 200 mm USB-A to USB-C. Connects the adapter output to the M3 sensor’s USB-C charging port.	Mounting screws For securing the bracket to a ceiling junction box or structural surface.

Specifications

Input	80–240V AC, 50–60Hz, Terminal Block. Double insulation; no protective earth (PE) required.
Output	5V DC, 500mA; USB-A port
Adapter dimensions	35 × 37 × 23 mm
Mounting bracket	108 mm diameter. Fits standard EU/US ceiling junction boxes.
USB cable	200 mm, USB-A to USB-C. M3 sensor only.
Network	Sensor continues to use Wi-Fi; no change to network connectivity

When to use the AC Power Adapter

The AC Power Adapter is the right choice when an accessible junction box can be wired by a certified electrician near the mounting location, and Wi-Fi connectivity is reliable at the property.

Best for	Apartments, STR units, and hotel rooms with an accessible junction box where battery maintenance is undesirable and hardwiring is feasible
Network	The sensor continues to use Wi-Fi; the AC adapter provides power only. If you need both wired power and wired network connectivity, use the PoE Adapter instead.

Installation

The USB cable is 200 mm (approximately 20 cm). Plan your mounting position so the adapter sits within 20 cm of the sensor inside the ceiling void, in the junction box, or surface-mounted alongside the bracket using cable trunking.

Choose your mounting location
Select a ceiling or wall location with an accessible junction box. The bracket fits standard ceiling junction boxes or can be screwed directly into a structural surface. This installation must be carried out by a certified electrician and may be subject to local electrical regulations.
Mount the bracket
Secure the mounting bracket to the ceiling junction box or structural surface using the included screws and a flathead screwdriver.
Connect the adapter
Have a certified electrician wire the AC Power Adapter's terminal block to the junction box's electrical supply. Connect the USB-A to USB-C cable from the adapter's output port to the USB-C port on the back of the M3 sensor.
The sensor powers on automatically once the USB-C cable is connected
Attach the sensor
Snap the M3 sensor onto the mounting bracket magnetically; the same way it attaches to the standard plate. Confirm the sensor shows a green light and is online in the Minut app.
Green light = online and monitoring

Already have the sensor installed? Use Sensor Swap to transfer all settings and data to the newly wired sensor without going through a full reinstall.

Battery protection mode

When the M3 is permanently connected to AC power, it automatically enters battery protection mode holding the battery at a slightly lower level than full to prevent long-term degradation from continuous charging. This is normal and expected.

What you may notice	Battery level in the app may show at 80–90% rather than 100% even while permanently powered.
Is monitoring affected?	No. All features work normally at all times.
Low battery alerts	Will not trigger for a permanently wired sensor. Battery maintenance is eliminated.

Compatibility

Compatible sensors	M3 sensor only. Not compatible with the M2 (Micro-USB port) or the E1 (has its own built-in power options).
Indoor only	For indoor installations only. Permanent wiring is not recommended for M3 sensors in outdoor mode.
Purchase	Available at store.minut.com. Select the AC Power Adapter kit at checkout.