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Full Version: Better to Leave Z Connected to AC Power?
OESF Portables Forum > General Forums > General Discussion
ArchiMark
Hi,

Have a C860 but assume this question would apply to everyone with a Z.

When it's convenient and available, is it better to

A) keep your Z connected to AC power or


cool.gif leave it disconnected and only connect it when the battery shows a low reading?

Thanks for any tips!

Mark
Tarquin
Not sure, but having been 'burnt' in the past byt the NiCad memory effect, I personally prefer to let the batteries run down.... :grin:
grey_moon
nicad work differently from li-ion, i'm guessing you are talkign about the memory effect of ni-cad
From what ive been told li-ion actually take damage each time they are fully discharged. They get damaged to a point where they stop charging. They guy who told me has 2 phds one in chemistry and another in some other material science thingy. I get really confused when he goes technical on me tongue.gif
I guess with li-ion what u have to be careful about is how the max number of recharge cycles is to be interperated.
grey_moon
Hoo hoo I hate it when someone makes a statement without backing it up, so here is a nice bit of info from the web
A lot of information bundles all the battery types into one maintainace info, but this one I find to be quite informative

http://www.buchmann.ca/chap8-page1.asp

"Is the Li-ion a better choice? Yes, for many applications. The Li-ion is a low maintenance battery which offers high energy, is lightweight and does not require periodic full discharge. No trickle charge is applied once the battery reaches full charge. The Li-ion battery can stay in most chargers until used. The charging process of a Li-ion is, in many ways, simpler and cleaner than that of nickel-based systems, but requires tighter tolerances. Repeated insertion into the charger or cradle does not affect the battery by inducing overcharge"
lardman
Ran?

There was lots of info/discussion/etc on the devnet. If I remember correctly the general consensus was to let the battery drain with normal use to about 60%, but never to let it go completely flat. Also Li-ions have a set charge cycle life.

Hopefully someone more knowledgable on the hardware front (Ran for example) can set us straight on this.


Si
desco
Back to the original question posed, I put my Zaurus on charge/external power ANY time I can. I have a power supply sitting under my desk at home, one at work, and one in the car. Because I've run into the embarassing situation of having it go dead on me, I trained myself to always plug it in every time I get to work or home. I really only use the car charger on longer trips, or when I'm using my Z as an MP3/OGG player.
grey_moon
I have to agree with desco here, nothing more useful then a powerless pda, especially if u have a 2 hour meeting to attend and u have 1/4 battery left... and if its boring and u want to catch up on some futurama episodes tongue.gif
offroadgeek
I definitely missed that thread on the devnet... bummer. I've been running my batteries completely dry before charging them.... it's actually a pain in the butt doing it.... letting it drain, then turning it on again to drain some more... oops... and I'm almost always near power :oops:
ScottYelich
I've been keeping mine plugged in almost 100% when I use it... ('cept when on subway, etc).

I, however, want to leave pdaXrom on my 760 on all day (plugged in) at home, so I can get to my
workstation... er... pda... from work.

Scott
Anonymous
Well, I'm certainly not an "expert": the author of that article that grey_moon clearly knows many times what I do about LiIon batteries.

My interpretation of what he wrote is that the battery is probably going to die in about 3 years, even if used "optimally". Charging it once or twice per day isn't going to have much effect on that, but charging it many times per day, or discharging it to "dead", probably will.

The bottom line seems to be that running the Z off the adapter is a good thing, but isn't going to make enough of a difference in battery life to be fanatical about it if you're using the Z intermittently. If you've got it on a lot of the time (e.g., using it as your MP3/Ogg player at work), though, it's likely to be worth picking up a 3rd-party adapter,

It seems pretty likely that making a fetish of putting the Z on the charger at every opprtunity to "top up" a battery that hasn't been discharged much is also bad. I'd like to hear what grey_moon's chemist friend has to say about that, though. because it's just a conclusion I drew from that webpage on battery life.

Ran
tumnus
From my experience you'd be lucky to get a rechargable lithium-ion battery to last 3 years. The battery in my Nokia 6210 started to not hold as much charge after only about a year. I've hardly ever let my phone battery run completely flat and I generally don't charge it when its above 75%.

My Sl-5500 battery lasted about 1 1/2 years before the charge it held, or rather lack of charge, became too frustrating so I had to get a new one. I ran my SL-5500 down a few times, but also kept it topped up on charge most of the time.

No one seems to know what is best, but I have heard repeatedly from eletrical engineering friends and model eletric plane enthusiasts that the worst thing you can do to a lithium battery is to keep discharging it completely.
lazy8
Wow, this place has really picked up since Zaurus.com went down. Glad to see it. I've kinda lost interest in my Z since the community collapsed, anyway here's my 2 cents for what it's worth.
I've had my Z for almost 2 years? seems longer than that but I have had the same two batteries since the beggining and discharge them fully before charging again. They have been cycled this way sometimes as many times as 2-3 a day. The batteries have begun to lose their charge faster now and even sometimes die when the Z is on full backlight with half battery still showing but given the number of times they have been charged and discharged I'd say they have held up pretty good over the last two years.
wigglit
So, why DID the Zaurus.com forum go down? Been wondering that for weeks...
tumnus
The website was being moved to a cheaper host and I guess they decided to revamp as part of it. They couldn't do two things concurrently, like run the old website while developing the new one, oh no (sarcasm). It is supposedly coming back at some point.

Getting back to Lithium batteries, I just remembered my wife's Compaq laptop came with a 'Battery Optimizer' app which charges the battery, completely discharges it and recharges it again. Whether that is really to do with maximising the battery life or just recalibrating the battery meter I don't know.
ironyengine
About the AC power issue, I've noticed that the amber LED that appears when the device is charging will inevitably eventually turn off after the battery is completely charged... I'm not sure if it's hardware or software telling it to do so but it seems to be able to recognize when it doesn't need to charge anymore, and stops sucking AC power at that point. I like to leave it plugged in whenever I'm at home, since I usually have the wireless card plugged in which consumes a good deal of power.
omega
Get yourselves a ipda usb sync/charge cable. So tiny, and as soon as you plug it in it starts charging happily away.
bluedevils
Someone posed this question at work (but it was about aqn ipaq). I did some research and this is what I came up with.

It is OK to recharge the battery before fully discharge as the li-ion battery does not have memory.

Depending on usage you should drain the battery once in a while (once a week or month?). This is not because of battery memory, but because there is circuitry in the battery that keeps track of the charge. I believe this circuit keeps track of charge and when to stop the charger from charging. If the discharge and recharge are constantly small, then the circuit has a hard time keeping an accurate track. If you do a long discharge and charge, then the circuit can recalibrate to be more accurate again.

It is bad to fully drain the battery because the battery circuitry will have no power. This is more of an inconvenience as the circuit just has to relearn things (requiring the long charge time).

I'll see if I can find my sources again......
omega
most Li-ion battery chargers, monitor by voltage the state of charge. So it automatically stops on that basis. If you use a usb cable to charge, it will charge slower and this also helps to preserve battery lifespan.
bluedevils
Here's a good place for information about batteries

http://www.batteryuniversity.com
Inuyasha
My personal use is to use the Zaurus for a few days without charging (number of days depends on how much I actually use it), and when it's down around 10-25%, I plug it in overnight and then go back to using it. Might not be the best way to do it, but so far it's worked for me (and for some odd reason the battery seems to last for a longer time than it did when I first got my 5600...)
waalkman
This is from when I had my iPAQ, but it applies to the Z as well.

Lithium-Ion batteries have a set number of charge-discharge cycles - 500 cycles if memory serves me. This means that you can do the charge-discharge thingie once a day for about a year and a half and then it dies (iPod owners know all about this).

So by all means keep it plugged in.


http://www.washingtonpost.com/ac2/wp-dyn?p...9¬Found=true

And ain't it sweet that we don't have to send the unit back to get a new battery smile.gif


John
ScottYelich
I keep my 760 plugged in all the time. my 700 is unplugged and is often dead without power.. takes a few minutes of being plugged in before it will even power on... and the 5600 is also not plugged in.
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