Hi all,
are below graphics a normal behavior for battery drop??
I think the dropped too fast from a “GOOD” state to a device OFF.
I’m using Energizer Ultimate Lithium batteries. Installed on November 2017
Stable on 3V for months and then dropped (the raise is because I replace temporarly with ikea’s batteries waiting for new Energizers).
The EUL’s in a Sky drawing more power do drop off like a cliff at the end of their lifetimes.
I don’t have any experience with the Air’s batteries going dead…since all three of mine are still running on their original batteries and at least one is way older than yours…
I agree with you but I expected some step in the middle… not a “GOOD” -> OFF transition. I was expecting some warning about batteries change before a full power cut-off.
The problem stems from the fact that Lithium batteries hold their voltage quite well right up until the end. The Air and Sky can only take a guess at battery health from the voltage, a very poor measure of capacity remaining, especially when starting capacity isn’t known.
The lithium batteries give 100% of their life, and fail quickly at the end as many of us have seen with the Sky. It is hard to select a warning voltage without the risk of throwing away perfectly viable batteries, since they hold such a steady voltage at the end (as your graph illustrates).
Speaking of Air batteries, my 4/2017 Air is likely gasping its last electrons out of its original EUL’s right now. 
It dropped from 3.01V to 2.79V in the past week. I have nothing to complain about getting over two years out of the original batteries. My graph is dropping a little less severely than yours, but still the norm for these batteries…
