Is Battery Drain Fixed In Newer Forerunner 955 Firmwares?

It's very difficult to give an opinion on this because, for example, with two different FR955s, have never experienced any battery drain issues in years. In fact, most of the problems I read about don't happen to me. I don't install any third-party apps or watchfaces, and maybe that helps, I don't know.

I haven't had battery issues with the latest firmware (23.xx+) 

My long term average is  0.391%/h.

What kind of drain are you seing? 

I'm now seeing 8-10% battery loss per day on days where I do no recorded training events such as a run or bike ride with WIFI and Bluetooth off and only pulse on and I'm using a watch face without seconds on it and no fields that update constantly.   I used to lose 3-4% per day on those same conditions/settings prior to updating the firmware many months ago.  I went for a run this morning, uploaded my data with WIFI, shut the WIFI off and did a watch shutdown using the menu item this morning and also reset my battery stats.  I'm hoping this might reduce the battery drain for the day since I noticed that some people said in other threads that there was a bug where after an activity the watch would stay in "Incident Detection" mode and burn up battery.  I don't have incident detection configured since I haven't even entered an emergency contact.  There was also supposedly a bug at one point related to auto-sync (which I have disabled) that caused some people to have their watch constantly try to sync after an activity endlessly.  I think they fixed the auto sync issue.... Not sure about the incident detection one. 

Garmin share is off.  I have pretty much everything off except for heart rate monitoring.

After going for a run this morning, then doing a WIFI sync, then shutting off WIFI, and then shutting off the watch using the "Power Off" menu item.. waiting a few minutes and powering it back on, my watch dropped from 51% to 50% after 6 hours and then from 50% to 49% after another 5.5 hours.

I rarely reboot my watch and I'm thinking the battery drain I have been experiencing consistently for months prior to this could likely be from one or some combination of:

1) GPS being stuck on after activity or Incident Detection turning on and staying on after a recorded training activity 

2) Memory leak in SW/FW leading to gradual decreased battery efficiency as watch uptime increases in the absence of a proper reboot.

3) WIFI-sync related problem that doesn't self-resolve by shutting off WIFI after the sync without a proper reboot immediately after. 

Either way... The reboot fixes it... So it's down to trying to identify for sure what condition causes it so I can at least know when I should reboot to prevent the drain from happening all the time.

I'll try to see if today's level of post-reboot slow drain remains consistent over the next day (to test for memory leaks), then do a WIFI sync without any runs being recorded to test for sync-related drains.  If that doesn't lead to drain, I'll go for a run and not sync after to see if that causes it.

6125703 said:

I've also noticed that bluetooth gets turned on by itself if I do the reboot step with holding down the LIGHT button for a long time. It doesn't keep the same state I had it in before the restart.

Don't use that to reboot. It doesn't save configuration changes and you will lose data. In very rare circumstances it may even corrupt things. It's the equivalent of yanking the power lead out of a PC or pressing its reset button.

If you want to reboot normally, use the proper power off function. That will make sure things are saved correctly.

You should only ever use the light button (watchdog) reboot when the watch is unresponsive and you can't power off the watch by any other method.

A fuller explanation is that there are two types of memory storage inside the watch:

• RAM: a small amount (a few megabytes) of fast access memory that is endlessly rewritable and low power, but needs power to keep its contents
• FLASH: a large amount (32 gigabytes) of slow memory that will keep its contents without power, but needs to be written in large chunks, and requires a lot more power than RAM to write to. It also has a limited lifetime in terms of how many times you can write to it.

What the watch does is that it keeps a working copy of configuration and the last few hours of watch-mode monitoring in RAM, only occasionally writing it to FLASH because writing to FLASH requires a much larger amount of battery power.

If you do a forced reset using the light button, the unwritten data in RAM is never made permanent in FLASH and is lost when the power turns off.

As part of the correct power off sequence everything that should be is written to FLASH so that it is available next time the watch is turned on.

If you are really unlucky with the light button reboot, you power off the watch whilst it's in the middle of writing to FLASH, and what is written will be corrupted.