BATTERY (855 not holding a full charge)

Have an 885T and experience similar situations with mine.
The battery runs down fast and just sitting loses power in one day.
I have heard that these Nuvi batteries have similar problems; some say that it is because it has to power certain areas even when turned off???

Experts in these field says that you should charge the unit fully and than let it get discharged fully before recharging them again.
This gives a good life cycles to the ions inside the battery.
Bu my question is if you are using Traffic data receiver like mine 255WT how can you let the unit get discharged fully? Each time you connect the traffic receiver unit starts charging too. This will decrease the life of your unit battery for sure.
May be in your case this can be a problem.
Let me tell you for 255WT, Garmin says it should hold charge for 4 hours. But even my unit is brand new hardly It lasts for 3 hours max. But I am not bothered as I am using traffic data daily. So any way I have to plug in the power cord to receive it all the time!!

Leave it unplugged overnight.

Try changing the battery

I had a similar problem with the original battery that I got with my 885T in May and I called Garmin and they sent me a new battery.

The date on the new battery was only a month old. My original battery date, that came with the unit, was about 1 year older than the new battery according to the date on the original battery.

The newer battery seems to do much better and now I have a spare extra battery. I received the new battery from Garmin in about 3 days.

The battery in my new 855 is dated April 2008. That seems pretty old, but so far it seems to be working OK. I suppose I should run a test to see how long it takes to drain from a full charge.

Leave it unplugged then charge it at home if possible. Cahrging at home would be better than charging in the car.

8x5 units go in Sleep Mode instead of turning off like other units. This gives you instant on, but it also depletes battery much quicker than other units.

So does my Magellan but you can force a "true" power off by holding down the power button for about 5 seconds. No such option for this Garmin model ??

Also, deep cycling a modern Lithium Ion battery accomplishes nothing because they do not have a memory and don't need to be "conditioned".

AND.....I see no reason to believe that one charging method is better than another. A full charge is the same regardless of how you get there.

On the 855, you can hold the the power switch for 10 seconds to reboot / reset, but it powers up / comes on. As far as I know, the only way to turn it completely off is remove the battery.