In some cases, the device can fail to detect a battery replacement, and it can think that the same batteries that were removed were re-inserted into the device. This typically happens when you swap between battery types before the batteries are depleted.

For instance, if you replace Lithium batteries - which have a higher starting output voltage than Alkaline batteries - with new Alkaline batteries before the lithium batteries are depleted, the device can think that the Lithium batteries were re-inserted because of the similar output voltage.

It is advised that because Airthings devices come with lithium batteries and if you need to replace them, we recommend using lithium batteries. It is best to replace the batteries before depletion to avoid gaps in data, and it is often better to replace all batteries at a location at once than go back and forth to replace devices one by one when they deplete. So please note that it is useful to keep track of when the batteries were replaced at each location to better plan the next visit because you can't always rely 100% on the battery indicator.

For more information on what type of batteries to use in your IAQ devices see here.