Hi all,

I need to build a battery powered digital thermometer that will operate at a low temperature for about 4-5 months (it will be placed outside at a -20 to -30 degrees Celsius).
What type of battery do you recommend for this low temperatures?
Which type of battery last longer (and operates normally) at such low temperatures? The circuit will operated at 3-5V and (in worst case) it will consume a current of about 2-4mA.

Thank you,

Buzai

 

I have used 6V alkaline lantern batteries to power data loggers that were required to run for 12 months in sub zero temperatures.

Your objective should be to reduce the current drain below 1mA. You can do this by using very low power microcontrollers that spend most of their time in sleep mode and are powered on occasionally (e.g. once each minute) to take readings.

 

Hello,

Have a look at this page from the battery-university:
http://batteryuniversity.com/learn/article/secondary_batteries

Bertus

 

Lithium primary cells could be the way forward, not cheap but you can get better deals online.

From:
http://data.energizer.com/PDFs/alkaline_appman.pdf
There's other useful stuff on the main page
http://data.energizer.com

 

I used to collect my companion's "dead" alkaline batteries on cold weather backpacking trips. Of course, the batteries still had half their energy once they got home and warm.