[prx984]

I just recently got a battery for my laptop (free) and I've noticed that it doesn't last nearly as long as my 3000 MaH battery for this laptop (I get about 3 - 3.5 hours depending on usage out of it). This new battery is 3800MaH and should last about 3.5 - 4 hours based on how much more capacity the battery has right? Wrong, this battery only lasts for about an hour and a half.

Now, I have decided to recalibrate the battery. That means, turning off all power management options and running the computer untill it just shuts off, not suspends or hibernates as this defeats the purpose. I have done that with this battery once already and got an hour and a half out of it (it was roughly 45 minutes before it got to 8%, yes it ran for 45 extra minutes after dropping below 8%) But, even after doing this, the battery meter still drops very quickly from about 75% to 8%.

Anyway, that's besides the point. I wanted to see how many people think a recalibration is a good thing, and how many think its a bad thing.

I'm going to say its a good thing, because, Li-Ion Batteries do suffer from the memory effect (From what I have seen, its purely experience). After cycles of charging them up from 75% to 100%, they eventually only last about 40% of their total capacity. So, running the computers until they just shut off, really does help fix the calibration in the battery. I have taken a battery from lasting 30 minutes up to 3.5 hours.

Also, some people say that deep discharging the battery isn't good for it, this may be true, but if you have to do it once or twice to get the battery back into calibration, whats 1 or 2 out of the projected 500 cycles it can handle?

Anyway, let's see what you guys think.

I think it works, just on some batteries though. I've only ever had 1 battery die on me for laptop/notebook computers. Thats out of about 10 I have had in the past.

This post has been edited by prx984: 03 January 2007 - 09:51 AM

[Maleko]

Yes, and it works for me!

Do it on anything that has a battery Fones, cameras, laptops etc...and always seems to improve it!

[Camarade_Tux]

I think it should work (and I have such an option in my bios) but I'm not gonna try since it's correct at 99% now.

[prx984]

Well, I'm still working on this new battery I got, and I just got 1 hour and 45 minutes from it, then it died. So I'm hoping I can get it to go a bit longer after a few more charges.

However, I think that maybe theres 1 or 2 cells in the pack that are dead. I know how these specific batteries work because I have repaired 2 or 3 of them by putting new cells in them. The batteries are 8 cells in total, and there are 4 packs of 2 wired in paralell to acheive 14.4/14.8 volts (depends on model number). Anyway, when one cell dies, the other cell in paralell to it takes on the load of running the computer though 1 battery instead of 2, so the current draw on it is much higher than before and this kills the battery faster (total life cycle's and a full charge).

So what I'm thinking with this battery, is the top half (above 50%) is still OK, but below 50% there is one cell either dead or dieing. So, if thats the case, I'll just have to keep my eye open for another battery. I got this one free anyway

[mark]

Oooh, dead cells, not good. Ok, so at this point I know that your battery has cells. A little info for you and anyone else that has batteries with cells. As I understand it, you do not want to run your battery down! From what I have read in the past and how I now treat any batteries I have with multiple cells is that once the battery starts to perform weakly (I don't know how you would determine that with your comp.) is to stop using it! What I have read is that juice from stronger cells will backflow to the weaker cell and permanently damage it. I don't know if this is what really happens or how but it is the way I treat my batteries and I am getting longer life out of my batteries. The second thing is, if you are charging your battery and the indicator says it is charged, it probably isn't. The sensor is thermally tripped and the batteries get warmer as they charge. So, leave them to charge more because they have more capacity than indicated. Don't try to get a good charge off a battery that is heated (like if you left it in a car that's parked in the sun). That's all I understand.


DL

[prx984]

I usually will leave my computer plugged in over night to fully charge the batteries. In the morning, the computer is always as cold as the room, so it's not generating any heat to damage the battery (Heat is generally bad for a Li-Ion battery, but cold above 32'f is ok).

The batteries that die young (ie, 1 year or less), usually have something wrong with them in the first place, and they never give the full charge (even when new).

And never leave a laptop inside a vehicle in direct sunlight, that is just asking for trouble (batteries die and other things can happen). Also, it usually means theifs can see it and will break in to take it.

[Camarade_Tux]

Li-Ion batteries are fun anyway : they tend to explode.
Don't play too much with them.

[prx984]

I havent had that problem, and I have repaired many laptop batteries, which all work just fine too

[ringfinger]

I reconfigure things, bring the LCD brightness down... turn off and unplug non essential devices... tends to save lots of juice

[prx984]

Those are good tips for saving battery, but this recalibration method usually can help you gain some extra run time on top of those tips you posted

[IcemanND]

I've had it work for some batteries and not for others. depends upon how the battery was used. The best recalibration I have seen is done by either built in recalibration software in the bios or dell used to have a recalibration software utility in the days of the latitude cpx that did wonders on batteries.

[Zxian]

You should also use a software tool to check the actual wear level on the battery. If the laptop is Intel based, you can use Notebook Hardware Control to check the battery wear level. I had a funny acting battery that I returned to Dell because it was defective (for a 25% wear level after only 5 months!).

[jaclaz]

Not ALL batteries are alike, recalibration might or might not be useful, depending on the exact type.

Here is an interesting site dedicated to batteries with technical info, that may help you decide whether it is advisable or not, hopefully with a reduced margin of error when compared to results of a poll:
http://www.batteryun...y.com/index.htm

jaclaz

[prx984]

IcemanND, on Jan 3 2007, 10:27 PM, said:

I've had it work for some batteries and not for others. depends upon how the battery was used. The best recalibration I have seen is done by either built in recalibration software in the bios or dell used to have a recalibration software utility in the days of the latitude cpx that did wonders on batteries.

Yah, this method doesn't work on all batteries, my dad has a Toshiba A10 laptop that has gone through 3 batteries already (company computer, not ours lol) and this method hasnt worked for any of those batteries.

Zxian, on Jan 3 2007, 11:59 PM, said:

You should also use a software tool to check the actual wear level on the battery. If the laptop is Intel based, you can use Notebook Hardware Control to check the battery wear level. I had a funny acting battery that I returned to Dell because it was defective (for a 25% wear level after only 5 months!).

Thank you so much for posting that, I had been looking for that program. I had this software a while ago and forgot where I had gotten it.

jaclaz, on Jan 4 2007, 04:26 AM, said:

Not ALL batteries are alike, recalibration might or might not be useful, depending on the exact type.

Here is an interesting site dedicated to batteries with technical info, that may help you decide whether it is advisable or not, hopefully with a reduced margin of error when compared to results of a poll:
http://www.batteryun...y.com/index.htm

jaclaz

I have read that actually

Anyway, this battery I just got for my Latitude CPi is started to work better. Sometimes what happens too, is because they haven't been in use very much or haven't been used for a long time, you can kind of revive them and make them work fairly well again. So far, I have it charging slowly (the way it should be) and it's lasting for about 2 hours now (up a half hour from the first rundown).

Thanks for the replies this far guys

[mark]

prx984, on Jan 3 2007, 04:33 PM, said:

I usually will leave my computer plugged in over night to fully charge the batteries. In the morning, the computer is always as cold as the room, so it's not generating any heat to damage the battery (Heat is generally bad for a Li-Ion battery, but cold above 32'f is ok).

The batteries that die young (ie, 1 year or less), usually have something wrong with them in the first place, and they never give the full charge (even when new).

And never leave a laptop inside a vehicle in direct sunlight, that is just asking for trouble (batteries die and other things can happen). Also, it usually means theifs can see it and will break in to take it.

All true. I can't speak for the batteries in laptops but when charging multicell batteries, the charging process can generate heat until it has finished charging. So, in the morning, your battery might have finished charging and cooled off by the time you get to it. But, I said, I'm not sure about laptops.

Regular use does seem to make batteries last longer.

I've not read the page indicated by jaclaz, but I will.


DL

[prx984]

IcemanND, on Jan 3 2007, 10:27 PM, said:

The best recalibration I have seen is done by either built in recalibration software in the bios or dell used to have a recalibration software utility in the days of the latitude cpx that did wonders on batteries.

I just re-read your post, do you happen to still have that software, or maybe know where I could get my hands on it? It looks as though this battery may not be able to be recalibrated by charging/killing it. I turned it on this morning, it said 100%, but it dropped to 9% in 20 minutes

I still have a good battery that gives me 2 and a half + hours, but I'd like to have 2 batteries.

[IcemanND]

Unfortunately, no. It didn't run on the newer systems so I tossed the copy I had. My only suggestion is to search Dell's site for the model you have. Sorry.

[prx984]

I already searched on DELL's website to no avail. They only had a recal program for the Inspiron 3000/7000/7500. That was all I could find anyway, I'll keep looking.

Thanks anyway

[IcemanND]

found this for the inspiron 7500: (may work with others don't know) http://support.us.dell.com/support/downloa...mp;fileid=20393

the Latitude LM and Inspiron 3000 and 3200 had it built in and it prompted you to run it.

[prx984]

Well, I will test this to see if it will work with the Latitude CPi

Thanks IcemanND!

Edit: It appears as though I may not need it any longer. The battery seems to be reading correctly now (I'm not going to hold my breath on it as its at 53% now).

This post has been edited by prx984: 04 January 2007 - 03:08 PM