Faster battery drain after FW update to 2.5.9?

Has anyone seen issues with battery consumption with FW 2.5.9 ?

I updated all my 6 tags about a month ago. Some have been running since 2018, so they are not new (all original CR2477). The FW update itself takes energy, so the sudden drop in voltage is expected. Still it did not recover given time as before, but kept dropping more. Most are now going down much faster than before, one almost dead.

I’m monitoring %, which is calculated simply by mapping linearly between 1.8-3V, 50% would be 2.4V. Before the update one node was reporting 98%. After the update ~55% for a day, which slowly (a week) got up to 70% and then kept going down. Another one reported 99% before, after update 92% and keep going down fast (92->80 in a month) and so on.

I know voltage goes down fast in the end of life (and my 1.8 low limit it quite low). Can it be that the FW update was just too much for old batteries, or has anyone seen similar?

I’m running RAWv2_SLOW, so expect less consumption than before. All these tags are inside, i.e. at stable temperature.

2.x firmware has synchronized battery measurements to radio activity. This gives a more realistic indication on how the battery is holding up during radio transmissions. has more details, in short this is what happens to battery during radio activity:*k7G_LgJGAIZj5X6zGOrfkg.png
That drop doesn’t really show up new batteries, but it gets rapidly worse toward the end of life of the battery.

1.x reports the unloaded blue line, while 2.x reports voltage at the X-line of above image.

sorry, missed that completely!

Could easily explain, batteries are getting old. I’ll replace and see.