Battery drain issue in not-ideal conditions (?)

Hi,

I would like to ask more experienced inReach users how they manage the battery life of their devices.

I got my inReach last Friday and went on 2 nights/days hike, sleeping outdoor with no indoor time at all. I have paired the device with iPhone X and Fenix 5+ and set it to log every 5 minutes & send location every hour. I have started tracking at 8pm. To my surprise, the battery was half empty the next day morning, after less than 12 hours.

I was blaming Bluetooth and/or ANT+ for the fact, mostly because I could not explain the battery drain otherwise and because I noticed that the Fenix watch battery was half-empty, too (no activity started). So, I have switched off both radios and hoped it will do better for the remaining part of my trip.

But the battery fell under 25% the same day evening, so the quarter of the battery was drained during the period of about 12 hours. I stopped the tracking. I tried to send a message. It took ages under trees. The next day morning, after around 8 hours, the battery fell under 10%.

I was very disappointed and thought I probably have a faulty unit, and I need to get it replaced / serviced. Before doing so, I wanted to do more tests, which I did:

I have charged the device fully, and let it powered on without tracking and touching it, next to a large window in my house. To my understanding, in this mode it should only check for new messages every hour. The battery drain was very fast (I don't have the exact figures here with me, but it was either 25 or 50% in either 24 or 30 hours) - much worse than the figures claimed by Garmin.

Then, I have charged the device again and went for an MTB ride. I have set the device to log every second and send location every 10 minutes, to drain the device as fast as I can. To my surprise, the battery was at 87% after 4 hours and a bit. So, in this mode and conditions, the battery would keep the device alive for 30 hours, exactly matching Garmin claims.

So here I am with very inconsistent results. The first hike where the battery fell short by far was mostly in forest with a lot of trees, often in quite narrow valleys. The MTB ride where the battery did well was in better conditions, but still with a part of it in deep forest. The tracking points were sent precisely every 10 minutes with no delays.

My current theory is that what drains the battery most is when the device is trying to send a tracking point or send/check for messages but is unable to do so because it cannot find the satellite, or the connection is very bad. And if that happens, it can suck the battery completely within few hours.

I have bought the device because I plan a 14-days long trip to place with no electricity, no cellular coverage, very little population and some (tiny) chance of being kidnapped by pirates or other armed extremist group operating in the area. I wanted to be able to leave a track of where I am to my family, and let my last location be available to a rescue services in case it is needed.

But I have no idea how to set the device to serve this purpose. If I keep it switched off and only send my location manually when having perfect view of the sky, I should be able to keep the device charged for the duration of a trip. But in such mode my last location logged may be easily 100 kms away. If I use the "extended tracking" mode and log every hour, I risk that the device will try to send a location under bad conditions, for example under heavy trees in a jungle, and it will drain the battery fast.

I would love Garmin to tweak the communication logic in a way it would stop trying to send a track point after some time in very bad conditions and instead retry again a little bit later. If this is done well (and technically achievable), it would solve my problem.

So, my question is: what are your experiences so far and how do you use the device when you need it to work for an extended period?

Thanks,
David

Top Replies

All Replies

0 WD over 6 years ago

Your battery is 1250 mAh, and the device can charge from USB, right? So you should be able to get approx. 10-12 charges from a good quality 16 Ah power bank. I have one of those, and it weighs around 330 gram. Could that be a solution?

If you watch the video Garmin made on the Mini, the specifically say that 50 hrs was conservative, to account for various conditions, and that 75 was the more accurate amount of time. That has not been the case in my use, and really was the topic of discussion here. The numbers do not seem to be marketed accurately. Half the battery life, at less than half the weight was part of the reason I switched from the Explorer SE+ to the MINI.

0 Dogbert62 over 6 years ago

All,

I am performing an additional test that should be closer to my use case; Extended tracking with a 4hr send interval and two preset message sends per day. I have also placed the device outside in the middle of the yard. I am getting ~ 0.67%/hr or approximately 150hrs. Again, BT, ANT+, Display backlight, etc.. are off. So...... either I am doing something wrong, the FW is still not dialed in, or the chart is way off. At 150hr life, I will need to turn the device off at night... not ideal..

Oddly, my first readpoint after a few hours was close to 0.75%/hr but it was 0.67%/hr after 24hrs. So, maybe (hopefully) the internal battery monitor is way off.

Regards
Dogbert

0 sousekd over 6 years ago

Extended tracking with a 4hr send interval...

Great. I would be very interested to hear the results when you are done. You should get 3900 hours minus 2 preset messages a day. 150 hours does seem only about 26 times less, so we are almost there :-).

I am performing a similar test, but I choose 10 minutes interval to drain the battery faster (just to compare with Garmin claims). With the 10 minutes interval, the test will not be representative of real world scenario tho, because when device doesn't move it only sends position every 4 hours I believe. But it should not affect your test, obviously.

0 twolpert over 6 years ago

I am performing a similar test, but I choose 10 minutes interval to drain the battery faster (just to compare with Garmin claims). With the 10 minutes interval, the test will not be representative of real world scenario tho, because when device doesn't move it only sends position every 4 hours I believe. But it should not affect your test, obviously.

The device does fall back to 4 hour send intervals when tracking (sending) and stationary. However, this is not the whole story with regard to battery drain. The unit will periodically use the GPS receiver to determine whether or not you are still stationary.

0 sousekd over 6 years ago

So I have tested the Extended Tracking with 10-min send interval, but without moving. In 24 hours, the device sent its position 6 times, every 4 hours, and went from 100% to 92%. It was placed indoors just under a very large rooftop window. Assuming linear battery drain, it would keep alive itself for 300 hours, which is more than 185 hours claimed for 10-min interval, but less than 575 hours claimed for 30-min interval.

And I have tested under exactly the same conditions, but with 1-hour send interval. In 48 hours, the device sent its position 12 times, every 4 hours, and went from 90% to 84%. If the battery indicator works correctly and is linear, it would keep alive itself for 800 hours, which is just slightly less than 1075 hours claimed for 1-hour interval. But keep in mind it was sending position 4-times less frequently...

Finally, I have tested under exactly the same conditions, but with 2-hour send interval. In a week (169,8 hours exactly), the device sent its position every 4 hours, and went from 100% to 84%. If the battery indicator works correctly and is linear, it would keep alive itself for 1061 hours, which is basically what Garmin claims for 1-hour interval, but significantly less than 2080 hours claimed for 2-hours interval. And it was sending position 2-times less often.

So I guess it is sort of a mixed bag. Not as bad as my initial findings suggested, but still not quite matching the spec.

The most important takeaway for me and new users is that a device with Extended Tracking started will actually consume less energy (depending on the settings) than a device in standby mode (regularly checking for new messages). This was not quite obvious to me.

0 Dogbert62 over 6 years ago

I made a huge mistake in my testing!!! I forgot to turn on tracking... honest.. but stupid mistake

So, after the first 22hrs using extended tracking with 4hr send and two preset messages per day with the device in open skies with tracking started , I am getting 730 hours lifetime.. This is much better than I need..

I will run it one more day or two to get a more accurate read..

Edit:
After 46hrs, I am at 1150hr lifetime.. This is roughly 50days which is much better than I need

Sorry for the confusion..
Dogbert62

0 Jesper_Kjaersgaard over 4 years ago in reply to WD

I know this post is +2 years, but your findings are right down my alley. I have another problem relating to this. When I connect my Garmin Fenix 5 to my Inreach, it drain my fenix 5 battery with 35% per day - without being connected to Inreach. Last night I removed the Inreach widget on my watch, and it is back to old drain - approx 2-3% over night.

So I when I need to use my watch with my Inreach, I will activate the widget and deactivate after use.

And I always bring a power bank to extend battery.

Rgds/Jesper

0 twolpert over 4 years ago in reply to Jesper_Kjaersgaard

Having the watch paired with the iR device AND the iR device off can sometimes be the worst case battery drain scenario for the watch. The watch assumes that the device is temporarily out of range - so it tries to reconnect more or less continuously.

It's not necessary to remove the widget. You can simply turn it off from Settings > Sensors & Accessories > inReach whatever > Status.

0 carleson over 4 years ago in reply to twolpert

Concur with all this - "searching" will drop the watch battery fast and set the status=off when not in an activity.