Being new to HA, I have only one week under my belt, and not know much about the performance of the battery, I have several questions. The first pair of batteries lasted 5.5 days x 15 hours/day = 85 hours. After fiddling the first day with programs and volume settings, I now keep the volume pretty low, the second notch from the bottom (2/16).
After replacing the batteries, I found out that the new spare batteries out of the package don’t last. They are size 312, mercury-free sold by Costco (they don’t say who the manufacturer is); I have two different expiration dates (different batches, all expiring in 2019), and they last one day. I’m trying to understand if the spare batteries I purchased suffered because of storage at the wrong temperature, or if there is something wrong with them. The specs I found for Energizer 312 all have a capacity of 160 mAh. I wanted to ask the knowledgeable people in this thread if they know the average mA drain or the electrical impedance of the HA, to be able to calculate the theoretical duration for the spare batteries.
I also measure the voltage of the batteries I take out the package with a voltmeter, and for some it reads around 1.39 V. For others it reads 1.1 V. Does anybody know up to what voltage does the HA hardware still work OK, and at what voltage does the low-battery alarm kick in?