Smallest sensor with greatest battery

[rdevine]

Does anyone have any insight into a battery size that will provide the most bang for your buck and be the smallest size possible? Im going to be creating temperature sensors and need the sensor to be as small as possible.

[gregl]

Theres a lot of variables in your question to be able to answer it properly.

If you only want to take one sample an hour then a cr2025 may last a year
but if you want a sample every minute then you might get a week...

so really how often do you want to send samples and how frequently are you happy to replace the battery.

There are a few boards out there with rf24 headers and CR2025 battery holders.
eg: http://harizanov.com/2013/06/the-workerb/img_2310/#main

[rdevine]

Its really a loaded question I know.

Being able to replace the battery may be an option, ideally i would like to avoid it.

[daulagari]

Not replacing the battery is not possible, most normal batteries are empty after eight years also if you do not use them.

[Dirk_H]

If you create a temperature sensor you should also have in mind the thermal performance of the battery you are using.

If you are in for rechargeable batteries: Lithium-Polymer will have the highest energy density AFAIK. However tehy perform bad with low temperatures. I'd probable do some research with LiFePo4 technology which performs better when its cold and also they are somewhat more robust.

I once worked for a company which developed sensors and such stuff to be used on the seas floor. They used Saft LS Lithium batteries - however they have not been rechargeable (nothing there to charge it with at some 1000m depth under water )

regards
Dirk_H

[diamantmatch]

@Dirk_H
I use LiFe batteries in my battery sensors. they are a bit oversized, but they work just fine.
And because of the lower operating voltage I don´t need any type of voltage regulation