How to replace the battery in Philips Hue switches and sensors

Which battery does your Hue device take?

To tell the two Dimmer Switches apart, look at the front button. If it carries the Philips Hue logo, it is the current model and takes a CR2032. If it does not, it is the older one and takes a CR2450. The two coin cells look alike but are not interchangeable: a CR2450 is 24.5 mm across and a CR2032 is 20 mm.

How to tell the battery is running low

• Dimmer Switch: a red blink just after you press a button means the battery needs replacing. An orange blink means it needs replacing soon. If the red flash keeps coming back with a new battery in, the switch has more likely lost its connection.
• Tap Dial Switch: an orange flash when pressed means a few months left. A red flash means a few weeks.
• Motion Sensors: a short orange flash when the sensor detects motion means the battery is low, and a short red flash means it is almost empty. The sensor only shows this the first time it sees motion after at least 15 seconds of none, so walk out of range and come back if you are checking.

If your accessories are paired to a Hue Bridge, the app shows battery status too. Open Settings, then Accessories, pick the device and scroll to the bottom. The wall switch module sits hidden behind your light switch, so the low-battery alert in the app is the only warning it gives.

Replacing the battery in a Hue Tap Dial Switch

Replacing the battery in a Hue Smart Button

Turn the Smart Button over and find the grey mark on the back, which shows where the battery compartment opens. Lift the back cover off with a small flat screwdriver, swap the old CR2032 for a new one, and press the cover back on.

Replacing the battery in a Hue Dimmer Switch

The Dimmer Switch sits on its wall plate with magnets, so start by pulling it off the plate. Turn it over, find the edge of the back cover and gently lift it with a small flat screwdriver. Swap the battery for the same type, sitting the same way round as the old one, then press the cover back on and return the switch to its plate.

If the cover does not lift easily, stop and check Hue's Dimmer Switch support page rather than forcing it.

Replacing the batteries in a Hue Motion Sensor

The indoor Motion Sensor takes two AAA batteries and the Outdoor Motion Sensor takes two AA. Take the sensor off its mount, open the battery cover, and fit the new batteries following the markings inside. Replace both at the same time rather than pairing a new battery with an old one.

If you would rather not change sensor batteries at all, Hue MotionAware uses your Hue lights to detect motion instead. It needs a Bridge Pro and at least three compatible Hue lights.

The wall switch module: book an electrician

The module lives in the wall box behind your light switch. Reaching its CR2450 means taking the switch off the wall and disconnecting the module before its cover comes off. Hue's own guide says to turn the power off at the switchboard first, and in most states that is work only a licensed electrician may do. Treat it as an electrician's job, not a DIY battery swap.

You will not need to do it often. Hue rates the battery for at least five years, so when the app flags it, add the swap to the next electrical job on your list. Our guide to Philips Hue and your wall switches compares the module with the options you can fit yourself.

Where to buy replacement batteries

CR2032, CR2450, AAA and AA are standard sizes, so any reputable brand in the right size will do. Supermarkets, chemists and hardware stores stock them, or you can order online:

• CR2032 batteries on Amazon Australia, for the current Dimmer Switch, the Tap Dial and the Smart Button
• CR2450 batteries on Amazon Australia, for the older Dimmer Switch and the wall switch module
• AAA batteries on Amazon Australia, for the indoor Motion Sensor
• AA batteries on Amazon Australia, for the Outdoor Motion Sensor