[camille]

right now, the battery for my PowerBook G4 is removed in favour of keeping it on my desk at all times in which it's purely run on AC. question is, is it safe to leave the battery in with the AC adaptor plugged in? would it overcharge the battery?

my mom's toshiba laptop battery suffered that problem w/ the battery being overcharged and thus can only have about 5 mins of battery life before it craps out. i dont want to have that problem w/ my PowerBook. thanks.

 

[roastpuff]

I would think that it wouldn't cause a problem... don't they have a cut-off circuit?

 

[kugino]

laptops have "smart" circuits that know when a battery is fully charged and then will leave it in a trickle-charge state, like most chargers do. don't worry about leaving it in.

i doubt that your mom's battery was "overcharged." batteries, in time, lose their ability to hold a charge for many different reasons. it wouldn't surprise me if you had to get a new battery for your powerbook even if you take great care of it...i've had to get new batteries for all my laptops after a few years...that's just how it is.

 

[Icarus]

The downside to lithium-ion batteries, the kind that notebook computers use, is they lose their ability to hold a charge over time. No matter what you do, you'll just get less and less runtime 'till the battery, finally, just won't hold a charge.
Lithium-ion batteries last about 3-4 years on average, and they generally are rather pricey.
If you don't use your Powerbook off the battery much, you should cycle it about every month, at least. Run your Powerbook off of the battery 'till it nears "empty", at which point it will automatically go into sleep mode. Then plug in the AC adaptor once again.
The worst thing you can do is leave your battery off of your Powerbook for extended periods of time; this will shorten the battery's life. Just keep the battery always connected to your Powerbook.

 

[ojnihs]

I've had my Powerbook for a good 3.5 years now and I've finally had to get a new battery for it. I just couldn't stand only getting like 20 minutes out of a full charge, especially since I'm in college and need to carry it around for random things throughout the day. It just happens unfortunately.

 

[Fallingwater]

I've always kept the battery in my Toshiba M30X and it's still in very good shape after two years.

 

[viator122]

I've had my iBook for about a year and a half. When I first got it, the battery would last about 4 hours. Now it will only last about an hour or less.

 

[marvin]

Care and feeding of Lithium Ion batteries.

 

[MacTheCat]

One thing to be aware of is that lithium ion batteries begin to degrade the moment that they are made. Even if an original apple battery is in its factory sealed box, it isn't a garuantee that it will hold a full charge. I know newer tech makes new batteries that fit in apples.

 

[krmathis]

I have had my 15" PowerBook G4 for close to three years, and I still get around 3 hours at a full charge. I have never removed the battery

 

[ilovesocks]

From what I gather through my research (which includes the link that marvin posted), the best things to do with laptop batteries (and indeed, all Li-Ions) are:

1) Keep the battery as cool as possible. Try to remove the battery and run on AC when you do heavy work which causes the CPU to heat up, etc. The cooler you keep your battery, the longer it will last in terms of lifetime.

2) Try to keep the battery fully charged most of the time. Small discharges and recharges cause less wear on the battery than long discharges and recharges. This isn't bad for the battery because it doesn't have "memory" like Nickel-Cadmium. This is how you should treat your battery most of the time.

3) Every [EDIT]once in a while[/EDIT], let the battery fully discharge (i.e. turn off all power management and let the laptop run until the battery dies completely - don't let the computer hibernate at 4% battery life or whatever the default is). Then charge it back up fully [EDIT] RIGHT AWAY.[/EDIT] This corrects the battery indicator, which gets thrown off over time as you give the battery little discharges and recharges.

4) If you're not going to use the battery for a long time, discharge it to 40% and put it in a cool place.

5) Overcharging shouldn't be a problem - what may cause degradation of battery life if you leave it in your laptop all the time is the possibly high temperatures from the computer to which it is exposed. Temperature is the biggest concern, as far as I can tell.

 

[Fallingwater]

Quote:

Originally Posted by ilovesocks /img/forum/go_quote.gif 3) Every month, let the battery fully discharge (i.e. turn off all power management and let the laptop run until the battery dies completely - don't let the computer hibernate at 4% battery life or whatever the default is). Then charge it back up fully. This corrects the battery indicator, which gets thrown off over time as you give the battery little discharges and recharges.

This is true, but one should NEVER discharge the battery to nothing and leave it like that. LiIon has a pretty low self-discharge when compared to NiMH, but it still has some. Let it discharge too much and the safety systems will probably kick in and prevent you from recharging it.
This is repairable, but requires opening the battery's case.

 

[bloodydoorknob]

yea, i charged my powerbook battery as frequently as possible in short periods and it lasted me a while.

 

[HiWire]

I leave my battery in. Generally, I try to keep the battery charged as often as possible, but run it on the battery every so often just to cycle it a little. I'm not too worried about the indicator, so I don't fully discharge it... apparently, that causes stress on the battery.

Slightly off topic: I have a Palm m505 from 2001 that is still limping along on its original lithium polymer battery. I can still get a few hours continuous use out of it (half a day) with the backlight off; with the backlight on, it gets about 2 hours of use. I guess lower-power applications allow the batteries to have a longer life.

 

[vagarach]

Full discharges of Li-ion (and even poly) are not good for the cells. The whole partial discharge/charge cycle is how they were designed to be used. Yes, maybe to calibrate your indicator, once in a while, but not regularly, to be sure.

I'm sure you've come to know with the news of late, but lithium battery technology can be prone to instabilities, although most cells are very resilient given abuse.