Problems with the battery status - Possible solutions?

[Themistokles]

Dear all,

I am quite happy with my Montana 700. I am using it on a regular basis on my MTBs. It has its drawbacks (due to Garmin's political decisions), but it measures the total ascent quite correctly, it is reliable (I don't use routing or address search, so can't tell about that), and it provides a big screen. It's the best device I've seen for a long time in this field.

However, there is one thing which I have ignored until now, hoping that a firmware update would fix it, but which is slowly going to become a PITA:

I normally use the AA adapter with three rechargeables to power the device. When I fully charge the batteries, insert them into the device and start riding, after approximately 30 minutes the red LED begins to blink, and the device warns about low batteries. However, if I ignore that warning, the batteries last for approximately 6 or even 7 hours. During that time, the warning is repeated one or two times.

I have tested normal batteries instead of rechargeables, with the same result.

This is really annoying because that way I only can guess when the batteries will be empty, and only if I remember how long I have used the device since I have recharged (or replaced) them.

Did anybody experience the same problem? Is there a solution?

P.S. Of course, I know that I have to tell the device the sort of batteries which are in place, and know how to do that. However, the problem described above always appears, whether or not that setting is correct, and independently of which sort of batteries I use (rechargeables or normal batteries).

[GPSrChive]

Which Firmware version is loaded on your Montana 700, and do you run the screen backlight on all the time?

[Themistokles]

Thanks for caring!

Currently I have FW 13.20 installed, the GPS software version is 2.90, and display software version is 85.07. I will upgrade to 15.20 during the next days, but I doubt that this upgrade solves the problem. Currently, the report of one user in the forum is keeping me from upgrading right now - I've got the impression that the new version does not work as it should, and I don't want to brick my device. Maybe I'll first upgrade to 15.10 as a compromise

Indeed, I have the screen backlight turned on permanently, but at the lowest intensity possible.

I usually ride during the day and mostly don't need the backlight, but from time to time, I might pass some quite dark spots in a forest where the backlight really helps even though it is at lowest intensity. I don't want to turn the backlight on in such situations, because that would involve a short stoppage of the ride. Therefore I have the backlight always turned on. As mentioned above, the lowest intensity is always sufficient for me, and it does not shorten the batteries' runtime too much.

[GPSrChive]

We are running v15.20 on both of our Montana 7x0 units, and would not hesitate to suggest updating to this version.

[Themistokles]

Thanks for sharing your experience. Then I'll upgrade to 15.20, too. Would you expect that update to fix the battery status problems?

You have asked whether I have turned on the backlight all the time. That question makes me suspect that you know something about it Could you please elaborate a bit?

[GPSrChive]

Update to 15.20, then do a test for us and turn the backlight off with fresh batteries and see if you get the same warnings and behavior...

[Themistokles]

Update to 15.20, then do a test for us and turn the backlight off with fresh batteries and see if you get the same warnings and behavior...

OK, thanks. I'll do that on my next ride and report back. Should I do that test with standard batteries or with rechargables?

[GPSrChive]

Which batteries do you normally see the issue with?

Test both if you can!

[Themistokles]

As mentioned above, I experience that issue with every kind of batteries: Normal batteries, normal rechargables (NiMH), and precharged rechargables with low self-discharge rate.

The only thing I haven't tried yet is the Lithium-Ion battery the device came with.

[Themistokles]

Sorry for the long delay. It's still winter here, where I am usually occasionally running instead riding my MTB. However, today I have done a first test:

I have used freshly charged rechargeables and have turned the backlight completely off. This did not change anything. After 30 minutes on my bike, the red LED began to blink, and the battery icon showed only one bar. From experience, I know that this situation won't change during the next 6 or 8 hours, before the device suddenly will turn off because the batteries are really empty then.

My next test (eventually tomorrow) will be with standard AA batteries and the backlight still turned off.

Best regards,

Themistokles