Battery life and how to change it

Every Locksure monitor and sensor runs on a replaceable CR2032 coin cell, typically 18 months depending on use. “Use” means how often the lock is turned and how far the monitor has to reach: a front door locked ten times a day with the hub in the next room uses the cell faster than a patio door locked once a night with the hub beside it.

Which battery to buy

A CR2032 from Panasonic or Varta. Not every CR2032 meets the specification the monitor needs; some cheap cells read a healthy voltage and still fail when the radio transmits. If a new cell seems to last only weeks, it is almost always the cell, not the monitor.

Changing the battery

1. Find the hole on the side of the monitor (the larger of the two).
2. Push the thick end of the wooden tool from the box straight into it, until the battery case opens on the opposite side and the old cell can be taken out.
3. Fit the new CR2032 with the + symbol facing outwards and close the case.
4. Lock and unlock the door once. Watch for cyan then amber, and check the hub or app updates. Nothing else needs re-pairing: the hub or your home app already knows this monitor.

You do not need to remove the monitor from the door to change the battery.

How will I know it is getting low?

• Original range: the app does not show a percentage, but the door tile shows a low-battery warning when the cell is below about 10%. If a door that always reported promptly starts missing turns, change the cell first.
• Matter range: your home app and the Locksure app show a battery percentage estimated from the cell’s voltage. A CR2032 holds its voltage for most of its life, so the figure sits at or near 100% for months and then falls quite quickly towards the end. Change the cell when it drops below about 20%; the Locksure app warns you at 10%.

Making the battery last

• Put the hub where it hears the monitor first time. A monitor that has to retry at higher power uses more. See Range and placement.
• Keep the hub powered. A monitor whose hub is off keeps retrying at higher power.
• Operating temperature is -8 to 40 C. An outside Key Turn monitor in a hard frost will read low until it warms up; that is the chemistry, not a fault.

Disposal

Take used coin cells to a battery recycling point (most supermarkets have one). Keep coin cells away from children: a swallowed CR2032 is a medical emergency.

Is the battery included?

Yes. Original monitors ship with a CR2032 in the box; Matter sensors ship with it fitted.

Is it rechargeable?

No. CR2032 cells are single-use. Rechargeable LIR2032 cells have a different voltage and should not be used.

Do I lose settings or pairing when I change the battery?

No. The monitor keeps its settings and its pairing. Lock and unlock once after the change and carry on.

Why did the Matter sensor’s battery stay at 100% for months and then drop fast?

Because the gauge is estimated from voltage, and a CR2032 holds its voltage for most of its life before falling away near the end. That is the chemistry, not a fault. Change the cell when it goes below about 20%.

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