Garmin Edge 530 power usage.
 

Using the navigation map in normal battery mode the unit switched to battery "safe mode" after 9 hours. Is this normal? Battery life new is 20 hrs. Unit is 2 yrs old.

Battery life depends on what you are using and in what mode. For 20 hours, I think you'd have to be in battery savings mode from the very start of your ride and not access the unit very often.

9 hours is about what I get before my Garmin Edge 530 asks if I wish to put it in battery save mode. Though that's only when I forget to charge it between several rides.

Do you have many sensors connected to it? These additional sensors (plus the mapping) can drain batteries faster.

Nine hours seems a little short if the device is fairly new though.

Thanks for responding.
I started the ride at about 97%.
I had the power sensor running the whole time, but did not use the Garmin varia radar to save power.
I also had the auto brightness enabled.
Now I selected the brightness to be 20%, and see if it makes a difference.

I don't think that a PM or radar is going to use very much of your Edges battery. I think that the Edge only has to listen for their transmissions and reception and the subsequent processing of that data just doesn't need much of your battery. It's times that your Edge has to transmit to something that also will use up it's power. And that includes the bluetooth connection to your Garmin Phone App.

Screen backlighting is one of the biggest user of your batteries power. So if you have it set to stay on all the time then change it to a short time out. It'll turn back on when you press a button. However I find that just changing the angle of the screen to my eye in differing height of the Sun above the horizon lets me see the screen well enough without the backlight.

So, I should disable bluetooth connection during long rides (brevets)?
Also, I should have the backlighting on a timer, and not continuously on. So you are saying that with the backlighting off I still will be able to see the screen during the day.
Thanks for the recommendations.

Backlighting & BT off should increase battery life a bit. Also, temps play a role in how the battery holds up. Colder = less battery time.

That's your call on the bluetooth. Depends on how badly you want the battery to last.

But if you've had the backlighting set to always on, then turn that to just 15 seconds or anything less than always on. You'll find that you can see the screen well enough. If you have it on a out front mount, then leave the mount just loose enough so you can adjust the angle of the Edge's display to your eye so you can see it easily without the backlighting on. The display backlighting will use the most of your battery that you can easily control.

Still, do you do 9 hour rides all the time? Or is it just that you don't charge your Edge between rides?

My usual rides are 3 to 4 hrs, and occasionally 6 hrs. Once in a while I'll do a 200k brevet which takes 10-12 hrs depending on the total ascent.
I charge the Garmin after every ride.

I'm not certain why Garmin says the Bluetooth is another source that one should turn off if you want to get the most out of your battery capacity. Bluetooth in itself is a very low power user even for transmissions. However if you use Garmin's live tracking, that might be making many BT transmissions all during the ride to the Garmin phone app if it's handled by the Edge.

So if you turn off BT, you won't have live tracking provided by your Garmin Edge 530. I don't know whether the Garmin App on the phone has the ability to use the phone GPS to do live tracking.