What is better for the battery?

[Papageoff]

... Push'er till she drops... or top off every night? I am rarely away from home for more than a day or two without my charger, I just don't want to charge it every night if it will screw up the battery.

[smoothjordan]

Actually, draining it will hurt more then help. There are many threads on this, but I advise you to keep it topped off. But if it's at 98 percent at the end of the day, don't worry about it.

[PalmCoaster424]

Are you sure? dosn't it get a set # of charges before you need a new battery?

[maceyr]

The LiOn batteries don't suffer from memory effects like the NiCd and NiMh. You should not let it drain much before charging. I know many people who still have the original battery and they charge it often. I charge it daily and have not experienced any deterioration in battery performance.

If you do, try doing a soft reset (pin in reset hole) while the palm is charging and let it charge for 3 - 4 hours and don't touch any buttons during that time. That usually helps recalibrate the battery and retain the charge better.

[junglemike]

Where all these ideas come from??
No - you _cannot_ hur the battery by deep discharging whatever you do, because even if you discharge it till critical warning (0%) - there is still about 30-60% of power remaining, and you cannot use whatever you do.
By the way, keeping your battery charged all the time will you _hurt_ it , and decrease it's lifetime. .
If you need to store your pda for longer time w/o using it - you have to discharge your battery to 30-40% state, and than store it, If you store it fully charged - it will deterriorate much faster (esp. in hotter temperatures).
See www.batteryuniversity.com for more technical info as well as this forum:
http://www.candlepowerforums.com/ubbthreads/postlist.php?Cat=&Board=UBB6&page=0&view=collapsed&sb=5&o=365

[applejosh]

By the way, keeping your battery charged all the time will you _hurt_ it , and decrease it's lifetime. .


I went to the battery univeristy, and I couldn't find where it said not fully discharging the battery can hurt the lifetime of a battery. The only thing I saw was that the "fuel guage" would become inaccurate (and wouldn't an in-cradle reset fix that should it develop on a Palm?).

[junglemike]

I went to the battery univeristy, and I couldn't find where it said not fully discharging the battery can hurt the lifetime of a battery.

I didn't say that. What i said - is that if you keeping your battery charged all the time (like live in cradle most of the time) - this will speed up the cell aging very fast. And the rason is that when lithium cell has high voltage (4.0-4.2v) - it ages much faster and than when it has lower voltage.
That's why all batteirs (and new palms) are always sold only 30% charged and not fully charged.
Another proof (from practice). Remember those old palm V and palm VX? - Guess what? - they are charged only to 4.0v ,and not 4.2v (as most palms do). BTW, i heard that T5 also only charges up to 4.0v - wise decision.
After 5-6years my old VX retained capacity much better, than my T3, which is only 1.5 years old.

But this all doesn't really important, cos most chances that you will have new palm, when it will be time to worry about the battery (unless you do anything bad, like charge your palm when it's cold)

[maceyr]

Sorry. What I meant in my post was charging it once a day, not keep it in the cradle all day. Use the Palm and then charge it at night. Regardless whether it's LiOn, it's a battery and it will eventually lose its ability to retain a charge. After 20 months, it's still working quite well for me with it being charged once per day.

[Cyker]

Interesting... until now, the general consensus has been to keep the battery topped off (Reasoning was that batteries do not have an infinite number of (full) charge cycles, but doing partial charges causes a lot less wear on the battery and doesn't eat into this hypothetical pool of charge cycles).

Now, what junglemike says makes sense about maintaining higher voltages causing increased cell wear, so it would appear that the best way to keep a battery is to keep it at around 50% permenantly and charge it when it gets to 40%... This isn't really worth it is it?

But you know what? It don't matter. Junglemike has that right too :D.
Chances are you won't have that PDA in 2 years time anyway, and if you do you'll be able to fit a new battery anyway. Don't hammer the battery unnecessarily (Like those nutters who, instead of charging a 50%-used battery to 100%, will drain it to 0% before doing a full charge - This Will Kill Batteries Faster), but don't baby it religiously.

I've had my TH55 for almost a year now, and the battery life hasn't altered noticably, and I have been keeping it topped up to 4.20v. Lowest it's drained to has been about 40%, with usual drain being to about 90% (That's an average day's use! :p :D)


On a related tangent, does anyone know where I can get replacement packs for a Tapwave Zodiac 2...? :D

[PalmCoaster424]

Interesting... until now, the general consensus has been to keep the battery topped off (Reasoning was that batteries do not have an infinite number of (full) charge cycles, but doing partial charges causes a lot less wear on the battery and doesn't eat into this hypothetical pool of charge cycles).

Now, what junglemike says makes sense about maintaining higher voltages causing increased cell wear, so it would appear that the best way to keep a battery is to keep it at around 50% permenantly and charge it when it gets to 40%... This isn't really worth it is it?

But you know what? It don't matter. Junglemike has that right too :D.
Chances are you won't have that PDA in 2 years time anyway, and if you do you'll be able to fit a new battery anyway. Don't hammer the battery unnecessarily (Like those nutters who, instead of charging a 50%-used battery to 100%, will drain it to 0% before doing a full charge - This Will Kill Batteries Faster), but don't baby it religiously.

I've had my TH55 for almost a year now, and the battery life hasn't altered noticably, and I have been keeping it topped up to 4.20v. Lowest it's drained to has been about 40%, with usual drain being to about 90% (That's an average day's use! :p :D)


On a related tangent, does anyone know where I can get replacement packs for a Tapwave Zodiac 2...? :D

I don't understand. How can I permanently keep it on 50% & recharge after 40% ,I can only let it charge 10%???

[junglemike]

Interesting... until now, the general consensus has been to keep the battery topped off (Reasoning was that batteries do not have an infinite number of (full) charge cycles, but doing partial charges causes a lot less wear on the battery and doesn't eat into this hypothetical pool of charge cycles).

That's right, and what I said doesnt' contradict to it. No matter if you discharge your palm completely, it it shuts off, or discharge it partially - it is STILL shallow discharge, becuae lowest voltage (depends on model) - is around 3.7v. Now look at any li-ion discharge curve like here:

So yes - partial (shallow) discharges (till ~3.7v) causes much less wear till full discharges (till 3.0 or 2.5v). But the only discharge that is possible with palms - is shallow one.


Now, what junglemike says makes sense about maintaining higher voltages causing increased cell wear, so it would appear that the best way to keep a battery is to keep it at around 50% permenantly and charge it when it gets to 40%... This isn't really worth it is it?

No, it definitely doesn't worth it. You have enought things to worry about. We are talking about pretty small differences. It's not like batt will die in 3 months or so. But trying to keep your batt topped off all the time not only doesn't worth worrying about, but also causes increased aging, as i explained before.
So the best thing to do - is just use your palm, as you use it. Well, if you gonna store your palm for 3 months - you better discharge batt till 30%, but in normal use - notheing special you need to do.



I've had my TH55 for almost a year now, and the battery life hasn't altered noticably, and I have been keeping it topped up to 4.20v. Lowest it's drained to has been about 40%, with usual drain being to about 90% (That's an average day's use! )


Yes, Th55's battery life is truly magnificent. I think they use very smart charging techniques to prolong batt life (like doing less trickle charge, when topped off).

Battery lifetime _greatly_ depends on battery quality. For example , all Nokia phones (all that i checked anyway) discharge their cells till around 3.0v (deep discharge), and Battery in my sister's old Nokia dropped from 4 days to 3 in 4 years of daily use!. That's arund 1500 cycles. And on the contrary, there are those crappy cheap cells (not original) that you need to change every 3 months, coz they die.