Love the built in resistors to measure the batteries. In an attempt to determine roughly how long 2xAAA batteries would last me I ran into an interesting finding. For those that work with small electronics and batteries all the time, probably not a surprise, but passing it on just the same.
In tracking my remaining voltage I noticed that using 2 batteries didn't give me what I expected. My plan was to monitor them until they got down to about 1V remaining and then send a notice to the device owner that it was time to replace the battery. Test project was running every 5s, doing a reading on a few things, mainly Voltage and as sitting fairly constant at 1.5V for the previous hour or so, next reading was 1V, next it no longer had enough juice to send something out.
It was about 3 hrs later when I got home and found it dead and the above results. In 10s it went from 1.5V, 1.0V, dead. Checking each battery, one showed 0.9V and the other 0.3V. Saw similar results on the other I'd been testing, but the logger had died during the time it powered off.
In a nutshell, the 2 batteries didn't discharge at the same rate, so trying to watch the battery remaining voltage, when using more than 1 battery in series has become problematic. So reverting to testing individual batteries AAA, AA, C, D to then compare cost to amp hour to space used in my enclosures.
I do love the writeup you've already done on batteries: https://talk2.wisen.com.au/2016/12/08/p ... y-battery/
Just wanted to point out what I've seen trying to utilize 2xAAA in a project so far in case someone else runs into the same issue, or more to the point makes the assumption like I did that they discharge at the same rate.
In tracking my remaining voltage I noticed that using 2 batteries didn't give me what I expected. My plan was to monitor them until they got down to about 1V remaining and then send a notice to the device owner that it was time to replace the battery. Test project was running every 5s, doing a reading on a few things, mainly Voltage and as sitting fairly constant at 1.5V for the previous hour or so, next reading was 1V, next it no longer had enough juice to send something out.
It was about 3 hrs later when I got home and found it dead and the above results. In 10s it went from 1.5V, 1.0V, dead. Checking each battery, one showed 0.9V and the other 0.3V. Saw similar results on the other I'd been testing, but the logger had died during the time it powered off.
In a nutshell, the 2 batteries didn't discharge at the same rate, so trying to watch the battery remaining voltage, when using more than 1 battery in series has become problematic. So reverting to testing individual batteries AAA, AA, C, D to then compare cost to amp hour to space used in my enclosures.
I do love the writeup you've already done on batteries: https://talk2.wisen.com.au/2016/12/08/p ... y-battery/
Just wanted to point out what I've seen trying to utilize 2xAAA in a project so far in case someone else runs into the same issue, or more to the point makes the assumption like I did that they discharge at the same rate.