firmware 12.50 battery drain issues

I went through whole thread and there are people, who mentioned having same battery drain issue with indoors ride with gps off.

I'm not one of these people. Mine has a significant difference with GPS on. When turned off ,battery consumption drops to an average of 5% per hour. GPS on increase it up to 30% per hour.

I did ride two days ago, almost 2 hours, using Edge 520 (v 12.5), Stages PM, and Garmin HRM. Battery took only 11% (from 87% to 76%) charge. Fit file included in the attachment.

Wow. I wish my 520 had that battery consumption. I did a 3.5 hour ride outside the other day. Stages PM, Wahoo HRM and followed a course. GPS only with no backlight on and no bluetooth. Started at 100%, went down to 20% by the end.

Upgraded to beta firmware, 12.53 and did almost same ride. 2:19:12 took 15% battery.

Could it be that battery drain is hardware fault? I have some experience with electronic devices draining battery, caused by water ingestion. Non rechargeable batteries that should last around 12 years would die within month.ciq.forums.garmin.com/.../1323893.png

Having been affected by high battery drain problems myself, I have come to the conclusion that it is the actual battery that is at fault with my 520. Colder weather drains the battery at twice the rate of warmer temperatures, with exactly the same setup. The thing is though - the critical temperature below which higher battery drain occurs is about 10 deg C. Ive tried with no GPS etc - but this made little difference. Seems to me that the battery is weak in the earlier units.
Really not happy considering my unit is just under 2 years old, and I can get the low battery warning with a little over 2 hours of riding at temps around freezing point. Only have PM, HRM and Speed sensors with around 50% backlight. Used to be around 13% drain/hr now it can be 40% plus in winter. I have to charge virtually every time I ride for 2 hours or more otherwise I have no idea how much battery life is left.

Has anyone who has a 520 with the battery problem replaced the battery? I wonder if the problem persists with a new battery.

It is not likely age of battery nor cold temperatures. IMO most likely an unfortunate firmware induced fault.
I have never connected my 520 to GC and have been happy with v9.1.
My 520 was placed in service June 2017, used for over 370 hours with over 150 charge cycles.
I have ridden 4 days a week over the past winter at temperatures under 5°C (1sec recording, PM, SP, CD, HRM).
Battery usage after a 4 hour ride has usually 70% or more remaining (with 20 minute satellite acquire and kept on during cafe breaks).

I too have had the edge 520 for several years now, ridden with it for thousands of miles and am seeing a consistent 25% battery drain per hour since the upgrade to 12.5. Of course it is my hope that Garmin recognizes the issue and works to resolve it quickly in the 12.6 update (as we have heard, no fix is included in 12.53). That being stated, the device is hardly usable on a 4+ hour ride now.
Apple recently did something similar with the older iPhones, and if this is the strategy from Garmin to force users to buy newer devices, I think they will find people will not tolerate that.

I have Edge 520 which i bought in August 2016, and have plenty of rides almost fault free (two times got rebooted in middle of ride without loosing anything,once with auto off enabled i got wrong time in fit file, so have to fix it, but otherwise no problems). I have 12.50 version of firmware, doing often long rides (more then 4 hours), and im connected to Favero Assioma Duo powermeter/cadence, HR strap and to my Redmi 3S mobile phone.Yesterday i had ride of moving time 04 hours, 27 minutes and total: 04 hours 56 minutes (i disabled auto off, so garmin is switched on even i make e break for cofee), and battery went from 100% to 56%. Also no problems in cold weather.

I think people need to realize that when posting a battery usage value you are unhappy with, that the backlight value has a substantial impact. I found early on that always on full backlight would completely deplete the battery in 2.5 hours from full...and that's when there were no problems with the firmware being reported, on a brand new device. I only use always on backlight at 50% as the usage of battery for anything over that is too high. Garmin should have never allowed a backlight settings that drain the battery that fast, because it is too easy to accidentally turn the backlight up too high and deplete your battery prematurely.