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General Forums => General Discussion => Topic started by: DaemonsGR on March 13, 2006, 10:04:50 am

Title: Battery Life! Read Me!
Post by: DaemonsGR on March 13, 2006, 10:04:50 am
From this site: Site (http://www.batteryuniversity.com/parttwo-34.htm)

Avoid frequent full discharges because this puts additional strain on the battery. Several partial discharges with frequent recharges are better for lithium-ion than one deep one. Recharging a partially charged lithium-ion does not cause harm because there is no memory. (In this respect, lithium-ion differs from nickel-based batteries.) Short battery life in a laptop is mainly cause by heat rather than charge / discharge patterns.


What do you believe about that? Should we charge Z before full discharge?

-Tasos
Title: Battery Life! Read Me!
Post by: Mjolinor on March 13, 2006, 10:20:47 am
Absolutely you should. IIRC it's best to keep LiIon and Li polymer at around 60% charge wherever possible. That maximises charge and life.
Title: Battery Life! Read Me!
Post by: bluedevils on March 13, 2006, 11:22:04 am
You do not need to fully discharge the battery like the nimh batteries.  Occasionally (once a month or longer depending on usage) you may want to do a deep discharge and recharge.  This will recalibrate the circuitry in the battery.  This circuitry keeps track of battery status so it doesn't overcharge.
Title: Battery Life! Read Me!
Post by: YoG on March 13, 2006, 12:15:33 pm
how do you "do a deep discharge and recharge"?
do you just leave the Z powered on until it's powered off?

YoG.
Title: Battery Life! Read Me!
Post by: Mjolinor on March 13, 2006, 01:07:34 pm
Normally the control circuitry will go into learn mode once the battery is discharged to the point where it won't turn on. It is also normal to stay in learn mode until fully charged so you shouldn't discharge then partially charge. It should be discharged and then left on charge until fully charged.

If the Zaurus has this type of charge circuitry then you are best just leaving it alone as turning it on when it is nearly charged can make the electronics think the charge is complete and it can leave you with a false full level.
Title: Battery Life! Read Me!
Post by: speculatrix on March 14, 2006, 07:13:05 pm
Quote
Normally the control circuitry will go into learn mode once the battery is discharged to the point where it won't turn on. It is also normal to stay in learn mode until fully charged so you shouldn't discharge then partially charge. It should be discharged and then left on charge until fully charged.

If the Zaurus has this type of charge circuitry then you are best just leaving it alone as turning it on when it is nearly charged can make the electronics think the charge is complete and it can leave you with a false full level.
[div align=\"right\"][a href=\"index.php?act=findpost&pid=118375\"][{POST_SNAPBACK}][/a][/div]

I'm not convinced the zaurus' charge control is that clever... I think it's a classic LiIon two phase charger: constant-current until the battery reaches a certain threshold voltage and then trickle charge until its "full". This was how most lithium chargers were made until coulomb counters and other sophisticated things were created.

One key thing is not to let the battery get too hot when charging, or, to use it when the battery is really really cold. That, AIUI, really reduces the life of the cells.
Title: Battery Life! Read Me!
Post by: xamindar on March 14, 2006, 07:31:33 pm
Quote
If the Zaurus has this type of charge circuitry then you are best just leaving it alone as turning it on when it is nearly charged can make the electronics think the charge is complete and it can leave you with a false full level.
[div align=\"right\"][a href=\"index.php?act=findpost&pid=118375\"][{POST_SNAPBACK}][/a][/div]

I can't imagine anyone wanting to design a charger in this way.  It would mean that if the battery was charged at 60% and you turn it on then all you can charge to from now on is 60%.  There would be a lot of upset people if this was the case.
Title: Battery Life! Read Me!
Post by: Mjolinor on March 15, 2006, 02:56:53 am
Quote
I can't imagine anyone wanting to design a charger in this way.  It would mean that if the battery was charged at 60% and you turn it on then all you can charge to from now on is 60%.  There would be a lot of upset people if this was the case.
[div align=\"right\"][a href=\"index.php?act=findpost&pid=118604\"][{POST_SNAPBACK}][/a][/div]

No, it only goes into learn mode at the low extreme of the charge cycle. If you have Linux on an Ipaq you can cat all the numbers and settings from the PROC directory. If you let it go as flat as you can then as soon as you apply a charger it writes that value to flash and uses it as the low reference. It stays in learn mode until fully charged or the charger is removed. That is why the instructions with an Ipaq tell you to fully charge it when new. It can lead to stupid problems if those numbers get screwed.
Title: Battery Life! Read Me!
Post by: Da_Blitz on March 15, 2006, 05:55:48 am
Intresting, i have noticed that i am getting reduced battery life and i do run the battery to about 10% each day (then it shuts down like windows CE, i dont care if i lose my current state as my data is on Flash)

guess i will have to recondition it, bat as i have external battery packs i might just top it up when not in use
Title: Battery Life! Read Me!
Post by: xamindar on March 15, 2006, 12:29:01 pm
Quote
i have external battery packs i might just top it up when not in use
[div align=\"right\"][a href=\"index.php?act=findpost&pid=118663\"][{POST_SNAPBACK}][/a][/div]

Could you post a pic of the external battery packs?  I'm curious.
Title: Battery Life! Read Me!
Post by: DaemonsGR on March 18, 2006, 10:12:30 am
Let me ask you smthng!
1) If you have use 20% of battery (80% remaining) do you plug it when you get home?(or office  )
2) If you have finished charging and working while in extrernal power and you unplug it for some hours without using it (lets say you did need it in your work) then you plug it again if you want to use it in the home?

I used to leave it to discharge to plug it again!

That do you believe?

thnx,
tasos
Title: Battery Life! Read Me!
Post by: bluedevils on March 18, 2006, 02:00:27 pm
1) yes when I know I will need a full charge later (the next time I use it)
2) it shouldn't do any real harm, but sometimes I just unplug it while doing some work at home anyways.
Title: Battery Life! Read Me!
Post by: Da_Blitz on March 18, 2006, 06:45:06 pm
http://www.lik-sang.com/info.php?category=...a78db437319a596 (http://www.lik-sang.com/info.php?category=307&products_id=8236&PHPSESSID=ee6f2a868608d1860a78db437319a596)

thats the battery pack i have
Title: Battery Life! Read Me!
Post by: DaemonsGR on March 19, 2006, 06:50:16 am
Quote
Let me ask you smthng!
1) If you have use 20% of battery (80% remaining) do you plug it when you get home?(or office  )
2) If you have finished charging and working while in extrernal power and you unplug it for some hours without using it (lets say you did need it in your work) then you plug it again if you want to use it in the home?

I used to leave it to discharge to plug it again!

That do you believe?

thnx,
tasos
[div align=\"right\"][a href=\"index.php?act=findpost&pid=119138\"][{POST_SNAPBACK}][/a][/div]


Anyone else doing this on li-ion batteries?
Title: Battery Life! Read Me!
Post by: pdahandyman on March 21, 2006, 05:25:14 pm
What about batteries that do not recharge correctly? I purchased a new EA-BL08 from LFL for $15 (its an aftermarket no-name brand) when my original would no longer charge, but the new one has the same issue. This leads me to think that its a power module issue or the OS I have on it (QTopia 2.1.2 on an SL-5600) just can't deal with the data. I also can't restore the original OS, but that's a post for another topic...

Any ideas?  
Title: Battery Life! Read Me!
Post by: bam on March 21, 2006, 09:36:57 pm
question, in cacko where can I set the warning levels, ie if I want the battery color to turn yellow @ 60% and red @ 30%