Laptop Li-Ion Batteries

[vontech]

I haven't been able to find an answer to this one here: For all us LAPTOP computer users:

What's the best way to "care for" laptop lithium ion batteries? I seem to have to replace mine every 8-12 months or so, and at $70 - $150 a throw, it gets really expensive! /ubbthreads/images/graemlins/banghead.gif /ubbthreads/images/graemlins/broke.gif

Typically now, I let them run down until I get a warning from my laptop (then I usually only have a few SECONDS to plug it in to AC charger before the laptop hibernates). The rest of the time, I simply leave it plugged in to the AC adapter.

I've always assumed that it would charge the batteries first, them operate on AC only. FYI, I have an AVERATEC laptop, and it indicates first that it is charging, then the charging light goes out and the AC light stays on.

Any of you battery "gurus" have any suggestions?

Thanks,

Tom

 

[PeterB]

The worst case for a LiIon cell is full charge combined with high temperature. Typically you have both, if you use your notebook with AC.
You might remove the battery after charging, but I don't know if this could have a negative influence on the power supply of the notebook (e.g. AC could be to weak for the maximum needed power).
You could also try to reduce temperature of the notebook...

 

[greenLED]

I unplug my battery after it's fully charged and run off AC. I don't worry about power outages 'cuz I have a UPS. /ubbthreads/images/graemlins/grin.gif I've had the same battery for almost 4 years now and it still gives me close to 4 hours of juice (max savings mode) when I travel.

PeterB, I don't understand how can AC be too weak for max power. /ubbthreads/images/graemlins/icon3.gif

 

[KevinL]

Hmm.. I'm not the kindest of users to my laptop batteries but they have generally lasted years and have had excellent capacity retention.

When away from AC power, I run them as long as it takes (usually till they hit zero). Whenever at AC power, I just run the laptop. If it decides to charge, it charges, if it's full, it stops. I've put many more charge cycles on my batteries than they're rated for, too. /ubbthreads/images/graemlins/icon3.gif I've had 4-hour batteries become 2.5 hour batteries after 3 years of use and abuse. That's still >50% capacity retention and I'm quite impressed. Now, if it fell below an hour I'd sit up and take notice.

I think it's got a lot to do with the quality of the cells, or maybe I am just lucky (I'm the last person I'd think of as lucky).

 

[enLIGHTenment]

Laptop battery life depends to a huge extent on design of the laptop and charge controller. Some laptops (<cough> DELL </cough>) will kill batteries within a year due to thermal issues and charger design. Dell's charge controller, for instance, eats up many charge cycles on the pack for no good reason whatsoever.

To prolong the life of laptop batteries when they are not going to be used for an extended period, follow the same rules as for other Li-ion batteries. Discharge the pack to 40% and leave it in the fridge. Don't freeze.

 

[PeterB]

[ QUOTE ]
greenLED said:
PeterB, I don't understand how can AC be too weak for max power. /ubbthreads/images/graemlins/icon3.gif

[/ QUOTE ]

What I meant is, that you can have rapid changes in the power consumption (e.g. when the processor goes from idle to full processing). For example the old windows didn't acitvate the power saving of the processors to avoid this changes which would be to rapid for cheap power supplies.
My fear is, that the notebook relies on the buffering of the battery and has therefore an AC supply with e.g. less buffer caps.
But thats only a consideration (don't know if it is really the case) and probably depends on the special notebook.

 

[270winchester]

What I have always done is use the laptop plugged in so it runs off of AC power most of the time, and every two weeks or so I run it down to cycle it, but as I can tell too many discharge cycles will hurt hte battery life. I don;t reccomend running the batts down alll the time, that's just asking for a replacement battery.

Nick

 

[rwolff]

I've heard from various sources that leaving a notebook computer plugged into A/C all the time abuses the battery pack (may vary from one manufacturer to another).

You might want to try what I do (I bought my notebook used, it came with a 3600 mAH pack that seemed pretty much "used up", I bought a new 5400 mAH pack). Whenever I need to leave it plugged in, I put in the 3600 pack. If I need to run on batteries, I go to the 5400 (plug in with this pack long enough to charge, then remove it and put in the 3600). I figure that if my machine is one that abuses its battery when it's plugged in for long periods, I may as well beat the #$%^& out of a battery that is already pretty much toast.

 

[SilverFox]

Hello Tom,

I just had to replace the battery pack in my Dell, however the old one lasted me 4 years.

The computer governs the method of charging, so there is not much you can do about that. Li-Ion is not tolerant of constant trickle charging, so I can venture a guess that some of the problem could be with the charging algorithm the computer uses.

Heat is another issue. Batteries are supposed to be good to 140 F, but cooler temperatures yield longer life.

Li-Ion cells will give more life when subjected to shallow cycles, rather than deep cycles. The computers battery gage may need an occasional deep cycle to recalibrate, but you will get more life by recharging often.

This also applies to the Li-Ion cells used in our lights, cell phones, PDA's, and BEV's.

The ideal situation would be to have two packs. Leave one in the computer all the time and understand it may have problems after a while. The second pack should be stored at about 3.8 volts or about 40% charge on your battery meter. When you know that you are going to need some portable power, put the second pack in and charge it up. When you are done with the trip, discharge the second pack to 40% and store it. Put the first pack in and carry on.

The problem I have with this is that I can never "plan" when I am going to need the second pack in order to get it charged up ahead of time. My solution is to keep the second pack at an 80% charge level. This level still gives me adequate run time if I need it right away, and takes less time to charge up if I am pressed for time.

Good luck with your new battery.

Tom

 

[KevinL]

[ QUOTE ]
enLIGHTenment said:
Laptop battery life depends to a huge extent on design of the laptop and charge controller. Some laptops (<cough> DELL </cough>) will kill batteries within a year due to thermal issues and charger design. Dell's charge controller, for instance, eats up many charge cycles on the pack for no good reason whatsoever.

[/ QUOTE ]

Maybe I have very special Dells and very special packs.... /ubbthreads/images/graemlins/grin.gif

Just kidding. I'm not trying to deny what you've seen, but over the years (1996 till present) all of mine have been good. Even the spare packs I've bought hold out very well. I don't baby the packs either, I just use them with the attitude that if they some day won't hold a charge, I'll just call and get another one.

Were yours Inspiron laptops? All of mine have been Latitudes - there seems to be a difference.

I work in a place where our people are using other brands of laptops as their main computers because of the mobility requirements, everybody seems to be yelling about dead batteries except me. /ubbthreads/images/graemlins/thinking.gif

 

[nethiker]

So...sounds like the typical CPF advice, just buy both (2 batteries). /ubbthreads/images/graemlins/grin.gif

Actually, I'm getting ready for another battery in my lappy, and I probobly would have recycled the old one if not for this thread. Keeping the old battery for home AC use makes perfect sense.

Thanks guys,
Greg

 

[James S]

the explanation of the fact that you don't have enough power in your adapter to power both the computer and the battery charger is probably correct. But I have trouble believing that this would be a design decision that they would make on purpose. Is this how it's always behaved? do other laptops of the same model have the same problem? (got to be a support board on the internet somewhere for them?) The charge controller in my machine is smart enough to charge at the trickle rate if you're using a 3rd party adaptor, (or some sub standard car or plane adaptor) or the high power rate if there is enough power available. And the plug in charger provides plenty of amps to both run the CPU at 100% and fast charge the battery... I'm thinking that you might need a new power adaptor, or one that provides more power. Are you using the adaptor that came with the thing? Or an aftermarket replacement?

it's quite possible that certain companies would ship a power brick that was incapable of actually powering the computer they are shipping it with, but that would make me rather angry at said company.

As far as taking care of the batteries, the advice others have given is pretty good here already. But you are completely at the mercy of the charge controller in your laptop when it comes down to it. Generally laptops, and most battery powered devices now days, are designed around pulling as much power out of the battery so that you get longer runtimes, and pumping more power more quickly into them to reduce charging time rather than prolonging the life of the batteries overall.

About the best practical advice is when you have access to power, use power. Your battery has only a limited number of cycles and with use it will reduce it's capacity. So carry your adaptor with you and find outlets if you want to preserve your battery. Personally when I want to use the battery I'm aware that I'm using up something and it doesn't bother me. I generally need a new battery every couple years.

 

[enLIGHTenment]

[ QUOTE ]
KevinL said:
Were yours Inspiron laptops? All of mine have been Latitudes - there seems to be a difference.

[/ QUOTE ]

Inspiron 8100. Its first battery went from 2h45m to 10m within 18 months. This seems to be pretty typical among Inspiron owners.

The problem with the Dell charge logic is that it never accepts that the battery is full and applies a charge pulse every minute or two. This eats into charge cycles like crazy, and when combined with the high temperatures that Inspiron laptops run at, results in a system which ensures that Dell earns considerable revenue selling replacement batteries.

 

[andrewwynn]

I have a computer that uses the same voltage power brick as a previous computer.... if i use the low amp power adapter.. it will let the battery stay at the same level and run the computer.. which lets me leave the battery 1/2 charged. I have seen studies which show that 40% charge is the best for LiON batteries for storage.

it's all a trade-off.. if you need lots of battery use and use your computer wireless.. it just ends up costing you a certain amount of money.. batteries are a consumable... just a fact of life.

-awr

 

[KevinL]

[ QUOTE ]
enLIGHTenment said:
[ QUOTE ]
KevinL said:
Were yours Inspiron laptops? All of mine have been Latitudes - there seems to be a difference.

[/ QUOTE ]

Inspiron 8100. Its first battery went from 2h45m to 10m within 18 months. This seems to be pretty typical among Inspiron owners.

The problem with the Dell charge logic is that it never accepts that the battery is full and applies a charge pulse every minute or two. This eats into charge cycles like crazy, and when combined with the high temperatures that Inspiron laptops run at, results in a system which ensures that Dell earns considerable revenue selling replacement batteries.

[/ QUOTE ]

Ah, I see. Such a steep capacity decrease would definitely be unacceptable to me and it would be noticed, yes. I'm fortunate enough to not have had this happen, but I'm dealing more with their Latitudes, and increasingly, their ultralights.

In this case it's definitely the fault of the charge controller, once lithium ions are done, they are done - no such thing as a trickle charge, or pulsed charge as they're trying to do.

 

[ViReN]

My last battery (on a Compaq Presario) battery lasted for about 3 years... it was like 2 hrs in begining.. and later on to 30 minutes... (i sold old laptop).... by that time...

My New...MAC's (Power Book G4's) battery is now 2 Years old lasts up to 3 hours now from previous 4.5 hours 2 yrs ago... I charge any time regardless of battery condition... every now and then....


My policy is simple.... power it up when ever possible.... and alternately.. use it till 30% left... (MAC OS X 10.3.6(and 10.2.8) gives warning when battery is at 30% level) before going in to power save mode when only 5% is left.

Charging frequently like this preserves my battery also prolongs battery life.

I charge once every month (if laptop is not in use) to topup the battery..... The battery looses about 12% in a month (ever since it was new)....

 

[LED_ASAP]

A little off-topic: When you go to buy a laptop, touch the bottom of the case and don't buy any model that feels hot like a toster /ubbthreads/images/graemlins/smile.gif

 

[SilverFox]

I use a device similar to this to keep my lap top cool during use at home. I believe it is well worth the money.

Tom

 

[James S]

Viren. there is a really neat little shell script for OSX that can parse the battery information out of the smart battery charger for you. Mine is only about 8 months old, but I use it on battery all the time, but not all the way down, just recharge any old time. the script is just called "battery" and you can find it at versiontracker.com or macupdate.com or PM me and I'll send it to you /ubbthreads/images/graemlins/smile.gif

my output looks like this:

Battery 1
Battery: battery installed, above warning level
Charger: charger connected, not charging
UPS: UPS not installed
System:
Voltage: 12.495V
Current: 0.000A
Charge: 4.332Ah of 4.357Ah (99.4%)
Capacity: 4.357Ah of 4.400Ah (99.0%)
Cycles: 80

So after 80 cycles I"m still getting 99% of the original capacity of the battery. Thats good battery management! It's interesting to watch the current that it applies to the battery as it charges up.

This is my main computer (after switching to powerbooks I've never bought another desktop or tower, just not that much faster or better /ubbthreads/images/graemlins/wink.gif ) and so I do use it sitting at my desk quite a bit. under it for cooling i use a Targus Coolpad which you can buy at any office max or similar place. Also gives you a better typing/viewing angle on the screen. it doesn't have a built in fan though like the one that silver fox links to. I actually have a little old power supply fan I put on the desk behind it that blows behind it and keeps things very cool but I run at a low power so it's very quiet. It's not necessary by any means, things run fine without it, but I just figure that cooler will last longer. Both battery and other parts too.

 

[ViReN]

Hey James... Thats Great Information /ubbthreads/images/graemlins/smile.gif

I had tried Battorox 1.X (on 10.3.X).... but after looking at my "dimming" battery day by day... my last reading was 87 % after 300 or so odd cycles... I stoped using it ... hehehe...

What Script are you using? It would be great if there is any good script for 10.2.8 ....

I am Eagerly Waiting for G5 Powerbook Announcement (Heat still is a issue) .... but its True PowerBooks Rock... Especially when you are involved in Professional kind of work.. Like Digital Mediagraphy.. including Photos & Videos

My Laptop's Most usage is for HDV & DV Editing ... Firewire 2 & 1 are of great help... I work mostly on 10.2.8 (find it more stable) .... for FCE ... and FCP is still a dream...

For Keeping the Laptop & Battery Cool... I simply keep it between two 1 inch thick books (Seperated atleast a feet apart, to accomodate the 17 Inch PB) and allow air to flow freely from below... this also helps me in connecting Firewire & USB cables & of course the charging cable .. you have suggested a great idea... I too have a cooling fan around.. will try this... /ubbthreads/images/graemlins/smile.gif

Feel like OS X is still under Evolution... with the announcement of 10.4 and path setting for 10.5 ....