You've been recording for months. You go back out in the field, anxious to retrieve the data you've collected. You check the SD card. There's not nearly as much data as you should have. The recording schedule that you programmed indicates that you should have been recording, and the SM2 itself is still functioning, but recording was only triggered a handful of times.
The SM2 has two battery bays: one for D batteries which run the unit, and one on the side, for 2 AA batteries which run the clock. Itâs easy to forget about the latter. After all, they only need to be changed once every year.
But neglecting to change them means that when the clock runs out, the programmed schedule has no trigger information...which leads to no recordings!
To prevent this, be sure to write down the date of the last battery change somewhere where it will be useful to you. You may even choose to write it on a slip of paper inside the battery compartment.
The battery compartment sits on the right side of the device, fixed to the unit by a patch of velcro. It's so snug that you may have trouble removing the batteries by hand.
To remove the tray, simply slip a credit card or similar object between the two pieces of the velcro to separate them. Then you can grab the battery tray and you're good to go!