I can't be sure that runners weren't using a small external battery (which is a practical option for Rogaine type events).
A couple of other things to consider:
- there is a "battery save" mode in MapRunF that defaults to OFF. Testing would be required to see how much it extended battery life in a real event. (This tries to power down the GPS when the phone is stationary)
- MapRunG on a Garmin has not been tested in long events (not to my knowledge). I imagine that different watch models may have different battery capacity.
I set up a trail event (rather than score) that took runners 5-6 hours. I was the only participant who managed to keep the phone going for the whole run and everyone else had to upload their gpx tracks from their watches. This made it quite a labour intensive process but luckily there weren't that many competitors.
I think for events of this length people need advice on battery optimisation and/or use of power packs. I'd have thought 3-4 hours should be OK for most people but you will always get folk who have old phones or start with insufficient charge!
Having tried "battery optimisation " at a local event on a Samsung I can safely say it is a load of 💩. That isn't MapRuns fault its simply the way it saves power means your GPS goes all over the place and takes up to 5 mins to lock on to a control, whilst standing and waiting next to it.
The Garmin GPS should on a full charge do about 5 hours use - however that is my experience from cycling, but would expect MapRun to be the same.
Just a caution on this about the 5 hrs - Every Garmin model is different in overall battery run time with GPS (not to mention the older the battery gets the the worse it gets) and any times noted by Garmin will be under perfect conditions and nothing extra running (bluetooth etc). I haven't bothered testing the impact of the MapRunG app running during the activity but this will have an impact. My wife is an utlra runner and her 945 can get "up to 36 hours" in GPS mode according to specs - never happens. She always packs a battery to recharge "on the run" (often multiple times).
I'm helping out with an upcoming 8 hr Adventure race that will be using MapRunF - the rules require everyone to have the ability to recharge their phones (or watches). Not sure how it will work but should be interesting!
I would exercise caution with any settings in a cellphone relating to battery optimisation. I've got a strong feeling (and repeatable evidence on one particular phone) that this causes the "go to sleep" problem. This advice does not apply to MapRun's battery optimisation which would work on the app specifically rather than the phone in general, and I look forward to comments on that.
We do a lot of 3-hour afterwork rogaines and I have been using my Samsung Galaxy A10 running Android 10 without problems. The event as a whole isn't published, just testing various things. After last night's event, and without recharging, its on 38%. This phone doesn't have the biggest battery in its class.