Battery charge, not what the icon says???

Doing a Google search will reveal a lot of good info concerning Lithium-ion batteries, one being Wikpedia. You'll find you should never completely discharge these batteries; in fact, there is no need to as they do not have the 'memory' fault as do some other batteries. Might want to check out that link as it has other important care issues relating to Li-ion batteries.

RT

Will it power back on when it's in this state? i.e. is the battery flat?

It's possible that it's crashing, rather than the powering-off.

If you fire it up in Maintenance Mode (hold bottom left during power up) and select "View Diagnostics", are there are crashes that match up with your 'power offs'?

Also, if you hold the Top-right of the screen (time) for about 7 seconds and enter the diagnostics, there's a battery test page (press Next a few times) that shows you the battery voltage, and charge remaining etc. (My Nüvi 310 operates until the voltage gets down to about 3.6V)

As RT stated above, unlike the old Ni-Cad, Li-ion batteires should not be deep discharged because you can damage it.

On the other hand, if Li-ion battery is constantly connected to a main power source and used infrequently, battery deterioration may occur faster if the battery is constantly charged at 100%. This is why my laptop comes with a software that lowers the charge threathold for its battery and periodically change the threshold level.

So with my 660, I frequently turn it on (mostly when I'm at my desk) just to draw the battey a little.

Say RT, your Wikipedia link is pointing to "http://www.poi-factory.com/filter/tips" and not "http://en.wikipedia.org/wiki/Lithium_ion_battery"

There is no question that Li-ion batteries are worlds better than their predecessors NiCd and NiMh. Both NiCds and NiMhs to a lesser extent,suffered from memory effects. That is that if you constantly charged them prior to them becoming almost discharged that ultimately they would develop internal shorts and the battery would no longer take a full charge (memory effect). There were chargers built to rejuvenate them by applying a fast hard discharge then zap them with a high charge which would effectively burn away those internal shorts. This only worked to an extent and prolonged the lifetime marginally. Longest life for these batteries occured with regular discharge/charge cycles. Sorry to run on on this.

Anyway, with Li-ion batteries they have no memory effect, their self discharge (unused time to just lose their charge sitting on a shelf) was also much better. They do not suffer from the memory effects above. In other words, you can charge them at virtually anytime. The more stringent requirement however on Li batteries is a very intelligent charging system. Virtually every one of these circuits apply a varying charge rate depending on discharged amount and always have both a full charge cutoff and a discharge percent cutoff. Most high-speed chargers also measure battery temperature to reduce charge rate if the battery starts overheating. In other words these circuits will not allow the battery to either overcharge nor discharge past safety margins.

RT was absolutely correct in stating that you NEVER want to let a Li battery fully discharge. Hence these smart charge circuits.

With this rather (I apologize) long-winded battery 101 explanation, you theoretically should never be able to hurt these batteries in a well designed device like Garmin GPSrs. In fact, the only thing that would hurt these batteries is to let it sit on a shelf discharged for many months till self discharge took it below battery safety levels.

Your normal charge/discharge process should not have hurt this battery. You didn't need to do this but the circuitry would normally protect it. The fact that your battery condition meter on the unit still shows 3 bars on crash, says that you have deeper problems than the battery. The diagnostic and maintenance screens mentioned by Phil may point you in the right direction but I suspect it's back to Garmin for that unit.

Rick

Sorry about that. Thanks for pointing that out and posting the correct link.
RT

On my c550 I had the same problem. I dropped it and after that i couldnt use it on battery anymore. I took it apart and the ribbon cable from the battery to the charger was unplugged. I plugged it back in and works perfect now. Hopefully this helps.

Thank you all for your comments. I will check up on several suggestions everyone made and post my findings.

Isn't the nuvi (and laptops) designed to shut down before the battery fully discharges? Wouldn't that prevent damage?

If you have a few minutes (LOL) please read my post above on how Lithium batteries charge and are protected. Know it's lengthy.

Rick

I charge my unit the same way you do. I have never had a problem yet. I have the c330 now for about 1 year and I never plug in unless the unit say low battery. I use it every other day and have to charge it once every 2 weeks. Sounds like you have a bad battery. Call Garmin up and they might replace the battery for you. The 1 time I called them, they were very helpful.
Rogersgps

Hornbyp,

Thank you for the suggestions. Here are my results:
1. When the unit abruptly powers off, I am not able to turn on unless external power is applied.

2. Maintenance mode: I found several "Abrupt power downs" listed in the diag screen. However these do not have a time/date stamp. They are just listed in sequence. So I cleared the log and I am waiting to see if I can duplicate the condition and record the event.

3. Test page: I did see the page that listed the details of the battery. The voltage fluctuates anywhere from 3.69 - 3.72, when fully charged.
I did not see any options to perform a test of any kind on the battery from that screen.

I think I may place a call to Tech Support...

Again thank you all for your suggestions.

That would seem to be the crux of your problem - it's not actually fully charged.
I just did a double check on my Nüvi 310 and Streetpilot C510 ... the battery voltage on both of them is 4.11V (they've both been on charge recently). 3.69 is about the point where they would switch off.

The information listed on the battery diagnostics page is what I mean by a "Battery Test Page". It shows you the external voltage that the unit is connected to, calculated battery capacity, charging state etc.

Eg.

Battery state "OK" or "Charging" or "Trickle"
VBattery 4.12V
VExternal 4.79 (rear USB connector)
BattCap 90 (I think this is a %age)
Battery Charge 15mA (this goes as high as 800mA when the battery is flat, but it's not particularly accurate (according to my multimeter).
Battery Chrg mAhr i.e. capacity = 1160
Charge Cycles 17

Given that your 360 shares firmware and a manual with my 310, I would have thought you should get similar results.

The three green bars you are getting, seem to be out of line with reality for whatever reason.