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stedders
Feb 28, 2003, 03:22 PM
I have a 500MHz PowerBook G4 just under two years old.

I really can't remember what the battery life used to be, but it appears to be have less time available.

It appears to only have one hour max, no matter what applications I am running.

How does this compare with other users?

FelixDerKater
Feb 28, 2003, 03:36 PM
One hour max? I get at least 3-4 hours on my TiBook 500 and it is about two years old.

ELYXR
Feb 28, 2003, 03:41 PM
If you go to the System Preferences and choose "Energy Saver"...
Then choose "Longest Battery Life" from the following options.

1. Highest Performance
2. Longest Battery Life
3. DVD Playback
4. Presentations

See if that works. ;)

zimv20
Feb 28, 2003, 03:44 PM
Originally posted by stedders

How does this compare with other users?

my lombard battery lasts 30 minutes if i'm lucky. the sad thing is it'll still say 2:30 hours when it turns itself off.

i suspect my problem was a combination of leaving the thing plugged in all the time (possibly cooking the battery) and then shelving the whole thing for a few months.

w/ my ibook, once it's charged, i unplug it and run off the battery. i hope this battery does better.

i suspect you've cooked your battery and it will never be any better.

stedders
Feb 28, 2003, 03:56 PM
Originally posted by zimv20
i suspect you've cooked your battery and it will never be any better.

Yes, I fear you may be right. Oh well!

Thanks to ELYXR (you learn something new every day); it has made a difference, but not an enormous one.

It will be interesting to compare the UK overpricing with the USA when I have to purchase my new battery!

alex_ant
Feb 28, 2003, 05:01 PM
You can't "cook" a battery. Some batteries vary in their longevity. Charging them up and then completely discharging them over and over again is much harder on a battery than charging it once and keeping it charged, and doing that will drastically reduce its lifespan. Charging a battery and then letting it sit in a closet for a few months is another great way to ruin it, because once the battery is at 100%, the computer stops charging it, and it will gradually (over several days or weeks) lose its charge. If you leave the battery in the AC-connected computer, and not in the closet, though, the computer will wait until the battery drops to 95% and then charge it up again. I leave my 14 month old TiBook on AC all the time, and I can still easily achieve 4 hours of battery life.

Maclicious
Feb 28, 2003, 05:03 PM
battery cooking?

You mean that leaving your iBook or powerbook plugged in all the time is bad?

Can anyone confirm this?

(it's certainly true that both my iBook and my wife's have seen a marked decrease in battery life over 1-2 years, and it is true that we tend to leave them plugged in overnight).

If true, I wonder if it is true on the newer charging cords, which seemingly indicate 1 colord (orange) when charging, then another color (green) when done charging.

Thanx!

yzedf
Feb 28, 2003, 05:11 PM
Originally posted by alex_ant
You can't "cook" a battery. Some batteries vary in their longevity. Charging them up and then completely discharging them over and over again is much harder on a battery than charging it once and keeping it charged, and doing that will drastically reduce its lifespan. Charging a battery and then letting it sit in a closet for a few months is another great way to ruin it, because once the battery is at 100%, the computer stops charging it, and it will gradually (over several days or weeks) lose its charge. If you leave the battery in the AC-connected computer, and not in the closet, though, the computer will wait until the battery drops to 95% and then charge it up again. I leave my 14 month old TiBook on AC all the time, and I can still easily achieve 4 hours of battery life.

To be blunt: wrong.

A battery loses it's max potential charge, true. Having it plugged into the wall all the time is bad. Just about every laptop ever made does not stop the battery from charging. That is why the battery gets so dang warm when it is always plugged in. More energy going in then out, difference is bled off thermally, just like a CPU.

If your laptop is going to be always plugged in, take out the battery. Top it off before you need it, and you will be fine.

A battery is designed to go from full flat to full charge to full flat. It is not designed to constantly have new charge coming in. It is designed to be a closed system, until it goes flat. Doing something other than that is just abusing the battery. And we all know that abuse is bad, regardless the type.

zimv20
Feb 28, 2003, 06:22 PM
from what i understand, power supplies can be either smart or stupid. smart ones will detect a full battery and stop trying to charge it. stupid ones will feed power to the battery regardless.

our batteries work via chemical reactions. iirc, charging it puts the molecules into an unstable state. left on their own, the molecules will form stable states, giving off electricity.

but too much charging can cause further reactions and make different stable molecules -- and react no further (i.e. no more electricity output).

i assume this happens, in some form or another, all the time. your battery life is an indicator of how much the internal chemicals have permanently stabilized.

please note the "iirc" above.

alex_ant
Feb 28, 2003, 06:48 PM
Originally posted by yzedf
To be blunt: wrong.

A battery loses it's max potential charge, true. Having it plugged into the wall all the time is bad. Just about every laptop ever made does not stop the battery from charging. That is why the battery gets so dang warm when it is always plugged in. More energy going in then out, difference is bled off thermally, just like a CPU.

If your laptop is going to be always plugged in, take out the battery. Top it off before you need it, and you will be fine.

A battery is designed to go from full flat to full charge to full flat. It is not designed to constantly have new charge coming in. It is designed to be a closed system, until it goes flat. Doing something other than that is just abusing the battery. And we all know that abuse is bad, regardless the type.
This is not true. I don't know what laptops you speak of, but the power adapters for the iBook and TiBook have different colored LEDs on the connector that goes to the computer, orange for charging, green for not charging. iBooks and TiBooks will not charge a battery if the battery has a 96-100% charge. It's true that continuing to charge a battery after it has already been charged will hurt the battery, but Apple laptops don't do this.

(Just to check, my TiBook has been running full-tilt for the past three hours on AC with a charged battery and the battery is room temperature.)

zimv20, that is correct. Apple AC adapters (at least the ones I know of, the white square one and the yo-yo one) are "smart."

KingArthur
Mar 1, 2003, 01:25 AM
"Cooking" a lithium ion battery is next to impossible. I tell you what does happen to them, though.....they lose their calibration. The battery starts thinking it is at its maximum capacity when it really isn't. I am not sure how, b/c I never have had to do it, but you can get programs that recalibrate lithium ion batteries. NiCa batteries could be cooked, and also could perminently lose a charge over time, but not lithium ion batteries. That is what I have been told by many computer repair people who have had to deal with this problem. Lithium ion batteries, from what I understand, cannot be overcharged like the old NiCa batteries could. True, there are always possibilities of losing cells in the battery due to a variety of reasons, but those are few and far between. To let you know, I have a Tangent laptop (yeah, it is a PC), and I keep it plugged in almost all the time. When I do unplug it to use on the road or something, it still has the same battery life as it always has.

My g-ma also has a 400mhz TiBook which she keeps plugged in as much as possible, and she still has no problem with it when she has to use it's battery.

zimv20
Mar 1, 2003, 02:25 AM
Originally posted by KingArthur
I am not sure how, b/c I never have had to do it, but you can get programs that recalibrate lithium ion batteries.

i'd read somewhere, maybe at apple help, the way to recalibrate is to run the battery dry and recharge it fully w/o using it.

i did that and my battery was still shot. but i'd be interested in knowing if there's another way.

KingArthur
Mar 1, 2003, 02:09 PM
That was the way to recalibrate the old NiCa batteries, and maybe it might help a little with LithiumIon batteries, but that is not the calibrating that I was referring to. I am a little busy to look right now to find how to recalibrate a battery, but if I get the chance, I will check.

TEG
Mar 1, 2003, 02:23 PM
On my TiBook, I get about 3-5 hours depending on screen brightness, and sound volume. I even played "The Sims" for 3 hours while stuck still on I-5 in Seattle, and still had about 25% of the battery left. I suggest you call Apple and get a new battery, or run the battery down untill it says you are on reserve power, then charge it up, that can refresh the batteries on them.

TEG