RearVue 820 battery draining in standby mode

poyo

Hello everyone,

I am experiencing a major battery issue with my RearVue 820 radar in standby mode.

If I don’t completely power off the radar and leave it in standby (so it reconnects automatically to the computer on the next start), the battery is often completely drained after 1–2 days of not being used.

Yesterday I fully charged it, and today the battery has already dropped by about 20% without using it.

Have you had similar experiences with the 820, or do you always power the device off completely?

  • 0

    Update:

    I did some additional testing and found something interesting.

    When I turn off my Edge 1050, the radar does not go into standby mode. The LED continues to blink green, which indicates it is still active.

    However, when I manually remove the radar sensor from the Edge 1050 sensor list, the radar immediately goes into standby mode (blue blinking LED).

    This makes it seem like the radar is still trying to maintain a connection even after the Edge is powered off, instead of automatically switching to standby. This appears to be a bug.

    Also, I am only able to pair the radar via Bluetooth. It does not show up as an ANT+ device on the Edge 1050.

    Can anyone with a RearVue 820 and Edge 1050 confirm this behavior?

  • 0

    Additional observation:

    I see the same behavior when using the Varia app on my iPhone.

    When I close the Varia app, the radar does not go into standby mode and the LED continues blinking green. In the iPhone Bluetooth settings, the Varia is shown as disconnected, but the radar still remains active instead of switching to standby (blue blinking LED).

    This suggests that the radar is not properly entering standby mode when the connected device disconnects.

  • 0

    Update on the standby behavior:

    After further testing, I can confirm that the radar does enter standby mode correctly when the Edge 1050 is powered off. However, there is a delay of about 1–2 minutes before the LED changes from green (active) to blue (standby).

    When I turn the Edge 1050 back on, the radar wakes up automatically without pressing the button.

    With the Varia app on the iPhone, the behavior is different. If the radar is in standby, the app does not wake it automatically — a short button press on the device is required.

    Also, the Varia app does not put the radar into standby when the app is closed. Since the app cannot wake the radar automatically, the power management behavior is different compared to using the Edge.

    My initial assumption was likely caused by not waiting long enough for the radar to enter standby mode.

  • 0 in reply to poyo

    If you use your iPhone using the Varia app, how are you putting it in standby mode?  Do you then turn your 1050 on and turn it off?

  • 0 in reply to mwada

    I normally do not use the Varia app, except for firmware updates or changing settings.

    When using only the iPhone app, the radar does not enter standby automatically when the app is closed. In that case, the only way to put it into standby is by pressing the button on the device.

    Automatic standby and wake behavior works correctly when using the Edge 1050. When I power off the Edge, the radar enters standby automatically after about 1–2 minutes, and when I turn the Edge back on, the radar wakes up automatically.

    So standby management works properly with the Edge, but not automatically when using only the iPhone app.

  • 0 in reply to poyo

    I only asked because I keep my bike in the room I am in all the time.  Yes, I don't use the Varia app also unless for maybe updates but I don't really know how to turn it off when using the Varia app.  I just cycled the switch until there was no tail light on.  I noticed it wasn't off but I didn't look for a blue light until you mentioned it.  When I just cycle the tail light off, I see the green light flashing AND I don't know the frequency but the tail light would flash occasionally. The reason for the battery drain?  The only way I know to put it in standby mode is to turn my 1040 on and off.  You mentioned that you pressed the button to turn it off or putting it into standby mode, is this just a short press or a long press?  And, when it turns off, does the blue light come on immediately or is there a delay?

  • 0 in reply to mwada

    To clarify, there is no way to put the radar into standby mode by pressing the button on the device.

    A long button press turns the radar completely off (no LED blinking at all). Standby mode (blue blinking LED) is only entered automatically when the connected Edge device is powered off.

    So when using only the Varia app, the radar does not enter standby automatically when the app is closed. The only option using the button is to turn the device completely off with a long press.

    Also, when the Edge is powered off, there is a delay of about 1–2 minutes before the radar enters standby and the blue LED starts blinking.

  • 0

    I'm facing the same issue with an Edge 850 and the Varia Android app. The device never went into standby (blue blinking mode). Now I have reset it (pushing the button for 10 seconds) and paired only the Edge. Now the standby works. I was about to return it because of the battery drain.

    Thanks for posting your problem here!

  • 0 in reply to poyo
    poyo said:

    It does not show up as an ANT+ device on the Edge 1050.

    Can anyone with a RearVue 820 and Edge 1050 confirm this behavior?

    I don‘t have this device, but I read DC Rainmakers review about the Varia 820, and he describes how to switch to ANT mode (it‘s complicatedRofl):

    https://www.dcrainmaker.com/2026/02/garmi-varia-rearvue-radar-820-in-depth-review.html

    You have to scroll down to section OLD COMPATIBILITY MODE (AND DISABLING THE NEW FEATURES)

  • 0 in reply to mcinner1

    There's a shortcut for this. Pair to the Varia 820 via ANT+ by having it connected via Secure Bluetooth to another EDGE unit at the time.

    I've just reproduced this with firmware 30.18 using an EDGE 1050 (Secure Bluetooth) and an EDGE 850 (Which showed the Varia 820 ANT+ Radar service which I was able to connect to.).