A notebook battery guide - Page 5

Nice helpful article for first time laptop buyers like myself

Speaking of batteries, does anyone know a good site to buy additional batteries from?
I am buying an Alienware m5550 and want a second battery to switch to when mine runs out while out in the world.

~Si

i have a MX6445 Gateway laptop, does anybody know thw battery life?

Hibernate = zero power drain...You can simply hibernate, and move elsewhere to plug....

Having said that, I really don't know if it is worthwhile to take all this pain...
I and a friend bought a Compaq V2000 each on the same day arnd 1.5 years ago...
Both of used have used the system pretty much the same (6-8 hours a day on average) albeit he followed this dischargebatteryto40%-remove-store-plug in nly when needed routine, whereas I just left my battery plugged in the system regardless of whether I was running it on AC or battery

Anyway, so for the last 1.5 yrs, both the machines have been used around 75%-25% on AC/DC respectively, and now, my battery wear level is 50% while his macine's battery wear is 38%

Unfortunately Li-Ion cells deteriorate with age, even if you do not use them at all and take as much of precautions that you can....
I wonder if that 12% difference over 1.5 years is really worth taking all this trouble

Byebye

if the battery is left out, the metal connectors can be exposed to dust, moisture, etc. the dirtier or more corroded the connectors are, the more resistance to the electrical current passing through them and the less efficient your battery will be.

My Friend owns a gateway m6445 and just leaves the battery plugged in his laptop everyday... he basically uses it as a desktop replacement and the battery led is blue meaning its fully charged. Is this ok? leaving the battery inside the laptop fully charged with ac plugged into wall?

battery charger

Does anyone know where to find a external battery charger for 9 cell batteries of a Dell latitude D620? I can not find one any where
Please help!!!

leaving batt in while on AC power

The computer has (or should have) the ability to stop charging the battery once it is fully charged. On mine, you can tell from Windows when it is charging and when it has stopped charging & is just on AC. The icon in the system tray (bottom rt-hand corner), if it is set to appear, will change from a plug-symbol with a lightning bolt (i.e. charging) to just a plain plug-symbol (AC only).

So, no harm is done to the battery. It just stops charging once it is at 100%.

good write up Adam, i didn't imagine the inside of the battery looked like that, figured it was one BIG battery not made up of small ones that you would otherwise see in an RC car..

Windows is not quite telling you the truth amd-xile.
In the most simple explaination laptop batteries are connected to the charge circuit via a diode which allows current to flow into the battery when another circuit which monitors battery voltage (and temp for a Li-ion battery) switches the charge circuit on.

Now the output of the battery and the regulated DC power from your wall socket are connected together via another couple of diodes. Because of the way AC adaptors are designed (what are called switch mode power supplies) they don't have much in the way of capacitive storage in them (makes them too heavy). Also switch mode power supplies take a finite amount of time to go from no power to full power that finite time would mean your CPU/GPU/memory/disk would have to wait until the power supply was able to provide enough current. Your nice responsive laptop game would all of a sudden become a laggy dog if there was no way to instantaneously provide that extra current demand.

This is where the laptop battery comes into play. Those peak current demands are met in some high powered laptops by pulling current from the battery which ultimately means it needs to be recharged a small amount from the charging circuit. These small charges are going on all the time. Windows would not even register them.

These small charges are one of the ways Li-ion batteries lose the ability to charge over time. Ni-Cd and Ni-mH batteries are worse again. All batteries except lead-acid work best when they are charged then fully discharged. Leaving a battery in a laptop shortens its life if you don't cycle it.

My recommendation is this - if your laptop will work without a battery in there when plugged into the wall socket take the battery out until you go portable. If you have to leave a battery in then get a second battery which you only use for portable use and swap it out when it is recharged.

My macbook keeps track of how many cycles the battery has on it; does anyone know how many cycles they are rated for? I have had the comp for about 3 months, I drain the battery to maby 20% every day, turn it off and plug it in untill its fully charged and then i leave it unpluged untill the next day. (Note it is lithium polymer, not lithium ion)

O.k., so I've read through the 6+ pages of posts. (Excellent article, BTW). I'm hearing that if the laptop is being used all day, the battery should be taken out. So if I decide to move to another room w/o power, I'll have to shut down, insert the battery, and then power back up? I don't want to ruin my battery but I also don't want to keep taking it out and putting it in. (When a docking station is used at the office, then the battery should come out?)

Juat a bit confused but want to do what is right.

Good info.

The question is, how DO you find out if/when you're laptop is tapping the battery, and how often, in these situations? Or does that just take sophisticated equipment/software that wouldn't be worth the trouble?

I brought this up because in most new rechargeable equipment --tools that use Li-ion batteries, for example, or electric motor vehicles-- charging is either computer-controlled or otherwise-controlled to cut off completely at 100% charge to avoid just this sort of power sipping and cycling. I assumed that the Windows power monitor was telling me that my lappy was doing the same thing. But you're right, of course, Windows wouldn't detect, or wouldn't report, that kind of repeated battery-accessing.

Thanks for your help you guys

thanks for the guide

first, a laptop should not be plug always in AC because it will decrease the life of the battery. Second keep your battery cool (40% charge), if not in use. Here's a complete summary.

Hey this is post is helpful to me also .

Thanks for the great information. I think that laptop battery life can be one of the most frustrating limitations of a mobile computer. I typically purchasing one more battery pack (sometimes even two more) and charge it every night to make sure I have all the power I need.
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I'm wondering if there is a way to check whether a battery drain problem is with the batteries or with the internal charge circuit. I have an iBook battery that lasts for 10 minutes when fully charged (shows 100%), but upon opening up the battery to replace the cells. They each show a 4.08v charge, which is at least what they should be. I'm wondering if this means that they are still good and the control board is bad, or if it only shows the operational voltage, which doesn't necessarily show how many amps they are capable of delivering. So when batteries drain, how far down do they drain in voltage and is this a clear indicator of drain, or must I check resistance or amps or something else? Thanks for any help.

Nice article! There's the same problem with my laptop. Thanks for your help.