Zumo User Forums

I learned something "new" a couple of days ago. Want to share it with you. If it was already widely known, then I am sorry for the wasted post.

I just received a new refurbished Zumo 396-LMT-S device. Out of the box, it wouldn't power up. When I connected it to my computer with the USB-data cable, it turned on and I spent an hour updating the device maps to 2026.2 maps.

After that, the screen showed a battery low indicator with a red flag. I figured I would put it the cradle on my bike and have it charge up there for a few hours. When I removed it after 3+ hours, it was still a red flag battery low. So I was concerned that the unit wasn't charging the battery.

A conversation with Garmin revealed that when the GPS ismounted in the cradle, t WILL NOT charge unless the GPS is powered ON. The rep from Garmin said this was to protect the bike's battery - figuring that you would only have the device on when the bike was running. He also suggested that I plug the 396 with USB cable into a charging block, like I have for my smart phone. The block charges the GPS at a quick rate, depending on the output amperage. He also said that the computer USB port was only providing a "trickle charge" and would take 12 hours or more to recharge the 396.

I called support back at GPSCITY to let them know that my "problem" was resolved, and the rep there was unaware that the GPS was not charging when mounted to the moto cradle even if the device was off.

MSTOCK27370 wrote: Mon Oct 13, 2025 12:35 am I learned something "new" a couple of days ago. Want to share it with you. If it was already widely known, then I am sorry for the wasted post.

Not a wasted post at all.

To be honest - I hadn't even thought about that - my cradle power is dead until I turn on ignition or accessories - so I would never have noticed.

I do know that the consumption / charge depends on how much extra power can be provided compared to the power that the zumo is using. So it can charge a little or a lot and anything in between. It can also discharge the battery slowly - if the power supplied is say 1.5A and it is using 2A or it can discharge quickly if the power supplied is much less. But the point is that it last longe if it is connected to a charging device of some sort.

I had noticed - from the unit on my desk which is is a cradle powered from a transformer that the charge symbol didn't seem to increase - but I hadn't taken sufficient notice of what it was like before I turned it off, so I hadn't drawn any conclusions.

So anyone with a flat Zumo thinking that they'll take it for a ride and let the bike charge it, would be very mistaken to think it will charge faster if it isn't using any power. THe only thing to do would be to dim the screen so that it isn't using as much power. Or better - have it on full brightness and go for a longer ride.

Thankyou for that info @MSTOCK27370