dim screen with power outlet and usb mini?

[truckinguy]

My screen is bright when using with battery charged. I just started using with a power outlet to mini usb on my snowmobile so I won't have to wire and or buy the amp mount with power line. And It seems the battery drains and screen stays dim do to lack of required amps from the poweroutlet and mini usb connector. It states it puts out 3 amps at 5 volts. It charges but with the screen full brightness,tracking on etc. it's just not enough I'm thinking.
I saw on Garmin fourm 4 yr old post a post was about the same. He thought too the screen was dim on usb mini power. And rigged up a power lead to amps mount.
I'll search for mini usb power outlet gadget with 5 amp but not sure if the garmin side will take it thru that. And I may have to get a powered amps mouunt installed.

[GPSrChive]

Which Montana model are you using?

The Montana 6x0 (Gen 1 + Gen 2) use mini USB, while the Montana 7x0 (Gen 1) use micro USB, and the Montana 7x0 (Gen 2) use USB-C.

[truckinguy]

thanks. got the 700 with micro usb I may just buy the amp mount. When I plug the micro usb in the screen dims a little. And may struggle to keep it charge? not sure yet.

[GPSrChive]

You are much better off with the AMPS Mount.

[LostAgain]

Amps mount is definitely better for using in or on a vehicle.
As well as supplying the correct voltage & amps to the unit, it allows to keep the cover over the micro USB port closed.
Over time the micro USB connector will wear from usage, vibrations etc..

When you plug it in and the brightness drops a little, can the brightness be turned up to full again manually?
Single press the power button should bring up the brightness menu.

[ConiKost]

Isn't that just normal? IIRC, Garmin has implemented, that Montana powered by 5V USB car mount or cable always limit maximum brightness, while not being in AMPS mount?

[LostAgain]

I think maybe it's sort of like an 'in mount' and 'out of mount' auto profile thing implemented by Garmin.
Dims when removed from the mount but can be set manually to full brightness after it's dimmed and still out of the mount, I think the 276CX and Montana 6xx series are similar at default settings.
I found the 7xx, 6xx & 276CX used to remember different brightnesses when in or out of the mounts once set manually.
All 3 have a random bug using the AMPS mount that the brightness goes to 100% when still in the mount and power to the mount is momentarily lost, like when starting a car or bike or something, particularly noticeable at night time when using the screen at lower brightness levels.
I thought it might be something to do with the auto switch from day to night mode but it seems more random and so far, not consistently repeatable.