Do I NEED to let the battery run down??

The manual that came with my 350 says that you should occasionally fully discharge the battery, then fully charge it without interruption in order to improve the accuracy of the battery guage.

Do that only if you care a lot about the battery gauge. Lithium-ion batteries do not need to be discharged fully, ever, and actually doing so wears them down more than keeping them charged.

http://www.batteryuniversity.com/partone-14A.htm

The run down only applies to Ni-MH or the older Ni-Cd battery to condition. For Li-ion, you should not do that and never let it discharge below 5% or you will seriously damage the cell. For Li-ion, it will permanently lose charge each year depend on the temperature and average charge hold. The best storage for it is in the fridge or room temperature with about 40% charge. A fully charged battery stored at room temperature for a year will permanently loose charge about 25% but drop down to 3-4 % in a fridge. So basically do not buy a Li-ion spare if you do not use it often or it will be a brick in a few years regardless using it or not.

Jeff

Is it the same percent for all Li-ions? My laptop fits that percent to a tee. New, it was good for about 3+ hours, now 4 years old 45 min.

No need to worry about how much you discharge the battery. The internal charge and monitor circuit of the Nuvi will monitor the battery level and automatically shut down the GPS if the battery gets below a certain point. It is impossible for you to run the battery down below that through normal use.

PT

I have noticed that if you cycle the batter couple times it tends to keep the battery in good shape.

I do it once in a month.Have been getting good performance for all my gadgets.

I use the same with my laptop batteries too..My last battery used to keep charge even after two years of use until it finally died recently.

If your battery drains completely, the only way to re-charge it is by connecting the USB cable to the computer USB port. The car charger and the wall charger won't recharge a completely drained battery.

I tried to reproduce this fault, the last time this was posted. I tested the following:-

• StreetPilot C510
• Nüvi 310
• Nüvi 760

None of them exhibited this problem. The firmware on the 1st two is (purposefully) not current. It may have been true of some model, at some time in the past - but it doesn't seem to be an issue at the moment...

...does the Nüvi 350 still suffer from it?

yes i would let it run down .

Well, now that we've all chimed in and everyone has given his opinion, I'm sure happybooker1 is thoroughly confused. I know I am.

Maybe confusing, but since bwarden was actually able to support his reasoning, I would go with that.

Maybe I should just call Garmin??

If you take a look at the link that bwarden added. This will tell you what to do with all your batters. Thank's for the link bwarden. I will keep a copy of the page close by.

ohwogo nuvi 750

To re-phrase a little: It's hard to do serious damage to a Li-I battery with normal use. You would have to try REALLY hard to get one to a completely discharged state....because the GPS shuts off before you get there.

So, from a practical standpoint......It just doesn't make any siginficant difference. Do whatever makes you feel good, in the knowlege that the little battery really doesn't care.

On the other side of the coin, if you are an occasionsal GPS user like me, and it might sit on the shelf for several months without being touched......it is probably a good idea to give it a full charge about once a month.......because a really LONG time of non-use might result in a completely discharged battery, which is not good.

Lithium-ion batteries also require sophisticated chargers that can carefully monitor the charge process. And because of their different shapes and sizes each type of Li-ion battery requires a charger designed to accommodate its particular size. This means lithium ion battery chargers are more expensive and more difficult to find than NiMH and NiCd battery chargers.

Lithium-ion batteries also have a lower self discharge rate than other types of rechargeable batteries. This means that once they are charged they will retain their charge for a longer time than other types of rechargeable batteries. NiMH and NiCd batteries can lose anywhere from 1-5% of their charge per day, (depending on the storage temperature) even if they are not installed in a device. Lithium-ion batteries will retain most of their charge even after months of storage.

So in summary; lithium-ion batteries can be smaller or lighter, have a higher voltage and hold a charge much longer than other types of batteries.

Try this site:

http://www.batteryuniversity.com/

http://www.batteryuniversity.com/parttwo-34.htm

That's a great read. Thanks for pointing out that site. I learned a lot more about proper use of Lithium batteries by reading that.

It appears that theft is not the only reason to take your GPSr with you, but extending it's battery life is too. It also sounds to me the best way to treat the battery is to take it off the car adapter an hour or two before I get home so it discharges a bit and then toss it in my fridge once I get there.

Just need to be careful to let it warm up again before I use it when it is humid. (The best thing to do is put it in a zip lock bag with the air squeezed out so no condensation forms on it as it warms up.)

If it isn't humid you can fire it right up.

According to that site, a user could retain as much as 94% of the battery's original capacity after a year by maintaining it this way. Nice!

As is often the case, what they DON'T say is almost as important as what they DO say.

Like: Even without storing it in the fridge, if you otherwise take reasonable care of it over that year (keep it at least 1/2 charged most of the time and don't expose it to temperature extremes)it will still have 85-90% of its original capacity. That is sometimes called "normal use".

I'm looking at maximizing the life of the battery for my "normal use". I use my unit a few times a week, rarely more. Unless there is a major upgrading of GPSr features and a radical lowing of their prices in the next couple of years, I can see myself still using this one for a long time to come. I just bought my unit a few months ago. 5 years is my horizon for a new unit, not 2 or 3, so extending the battery life by tossing it in the fridge is trivial for me. I don't really think of it any differently than the other batteries I have in there now or the film that is in my freezer.