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Hedgecore's Avatar
Posts: 1,361 | Thanked: 115 times | Joined on Oct 2005 @ Toronto, Ontario, Canada
#1
I leave my battery charging at night whether dead or not and use the 770 for short stints throughout the day, leaving it in offline mode on standby. I always come home to four battery bars during which time I use it unplugged and it seems to go to half. Otherwise during long weekend runs it lasts more than 3h ours while online and connected. (I don't play movies or mp3s that much). I've had it for over 3 weeks now.

What are your usage trends, charging trends, and battery life?
 
Posts: 191 | Thanked: 9 times | Joined on Nov 2005
#2
Did you condition the battery when you first got it? I gave mine several cycles of full charge then full discharge and now I am getting better than stated battery life. Almost 5 hours using wireless. I use it during the day and it sometimes drops to 3 bars. Then I charge it at night. Back at work next week so I shall see how it goes then on the move and away from the charger.

One thing I have heard is with these sorts of batteries every so often it can help to let the battery get quite low rather than always having it near full charge. Not for the battery so much but rather so the power circuits in the device stay in calibration. No idea if that is true or not!
 
Karel Jansens's Avatar
Posts: 3,220 | Thanked: 326 times | Joined on Oct 2005 @ "Almost there!" (Monte Christo, Count of)
#3
For those who want to know everything knowable about batteries:

http://www.batteryuniversity.com/index.htm
 
zupidupi's Avatar
Posts: 22 | Thanked: 2 times | Joined on Nov 2005
#4
Hi folks,

Good and interesting site, thx for the link. I didn't manage to figure out one thing, though. I listen to my mp3-collection through my 770, streaming the music to the tablet from my main computer on which I have installed a Shoutcast server. Obviously this continous use chews up a lot of battery life. Is it better to have it on recharge all the time while listening to music, or should I start charging it when the battery runs low?

Wonders

Zup
 
Hedgecore's Avatar
Posts: 1,361 | Thanked: 115 times | Joined on Oct 2005 @ Toronto, Ontario, Canada
#5
Simon: Not exactly. I jumped the gun and gave it a 45 min charge in a Krispy Kreme (Yes, I stole electricity long before I stole wireless) in Michigan before heading back over the border. I used it for about an hour in the car and then gave it a full charge when I got home. For the next few days I went through about 3 power up - power down cycles. From home use I get about 4 hours (I'm guessing here). I also set up a 10Mw connection for when I'm in the appt and the battery bar has never budged (no music being played tho).
 
Posts: 45 | Thanked: 2 times | Joined on Nov 2005
#6
Originally Posted by Simon
Did you condition the battery when you first got it? I gave mine several cycles of full charge then full discharge and now I am getting better than stated battery life. Almost 5 hours using wireless. I use it during the day and it sometimes drops to 3 bars. Then I charge it at night. Back at work next week so I shall see how it goes then on the move and away from the charger.

One thing I have heard is with these sorts of batteries every so often it can help to let the battery get quite low rather than always having it near full charge. Not for the battery so much but rather so the power circuits in the device stay in calibration. No idea if that is true or not!

you should NEVER fully discharge a Lithium Ion battery!

And I quote from Wikipedia (you can verify from any other source on Li-ion batteries:
While Li-ion batteries do not suffer from the memory effect, they are not as durable as NiMH or NiCd designs and can be extremely dangerous if mistreated. At a typical 100% charge level (notebook battery, full most of the time) at 25 degrees Celsius, Li-ion batteries irreversibly lose approximately 20% capacity per year from the time they are manufactured, even when unused. (6% at 0 °C, 20% at 25 °C, 35% at 40 °C). When stored at 40% charge level, these figures are reduced to 2%, 4%, 15% at 0, 25 and 40 degrees Celsius respectively.) Every (deep) discharge cycle decreases their capacity. The degradation is sloped such that 100 cycles leave the battery with about 75% to 85% of the original. When used in notebook computers or cellular phones, this rate of deterioration means that after three to five years the battery will have capacities too low to be still usable.


Do not cycle your Lithium Ion batteries!
Now while the Nokia uses Lithium polymere batteries its the same thing basically. It will have a longer discharge-charge cycle life but it is not reccomended to discharge/charge it as that does decrease it's life considerably faster than normal usage.

This is for NiCad and NiMH batteries only.

Last edited by skynetos; 2006-01-06 at 14:31.
 
Posts: 74 | Thanked: 4 times | Joined on Dec 2005
#7
Originally Posted by skynetos
you should NEVER fully discharge a Lithium Ion battery!
...
Every (deep) discharge cycle decreases their capacity.
What is considered to be "deep" charging? I assume using the device until it switches off is considered to be fully discharging.

When the device starts informing of battery low, is this also considered to be discharged, or is this ok?
 
Posts: 45 | Thanked: 2 times | Joined on Nov 2005
#8
nah what a deep cycle is basically running it till it wont even turn on anymore, not even a blip on the screen. Having the device say "batt is low" is fine.. what that really means is "you have 10 min left shut me down or save your work".
 
Posts: 50 | Thanked: 0 times | Joined on Nov 2005
#9
Actually, if the internal charging/supply circuit does what it's supposed to do, it will never fully discharge. Instead, the device will shut down at the battery's lowest safe discharge level. This reduces the definite damage caused by a "deep cycle".

That was an interesting wikapedia article. I think I'll be storing my unused lipolys in the freezer from now on!
 
Posts: 45 | Thanked: 2 times | Joined on Nov 2005
#10
well..its still not good to run them down..ever.. you always want them to be TOPPED off...
 
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