Full charge capacity vs. Number of charge cycles.

Message

Chatbox · #1 Post by **Chatbox** » Wed Jul 21, 2004 1:55 am

Please post the following infos of your thinkpad batteries:
Model of thinkpad
Number of cells
Design capacity
Full charge capacity
Number of charge cycles
Number of months since the manufactured date.

I'm trying to see how mine compares to other people out there.

Leon · #2 Post by **Leon** » Wed Jul 21, 2004 3:14 am

Model of thinkpad T42
Number of cells 6
Design capacity 47.52
Full charge capacity 42.31
Number of charge cycles 26
Manufactured date. 2004-06-03
First Use Date 2004-06

Changed a little, should give manufacture and first use date... what about ur #s chatbox?

bsod · #3 Post by **bsod** » Wed Jul 21, 2004 7:41 am

Hello everyone (first post),

Model of thinkpad T40p
Number of cells 9 (?)
Design capacity 71,28
Full charge capacity 53,84
Number of charge cycles 121
Manufactured date. 2003-09-09
First Use Date 2003-12

I worry a little about the decrease of the capacity ...

would · #4 Post by **would** » Wed Jul 21, 2004 7:55 am

Model of thinkpad: T41p
Number of cells: 9
Design capacity: 71,20
Full charge capacity: 68,12
Number of charge cycles: 31
Manufactured date. 2003-11-09
First Use Date 2004-01

nesen · #5 Post by **nesen** » Wed Jul 21, 2004 8:04 am

Model of thinkpad: T41p
Numer of cells: 9
Design capacity: 71,28
Full charge capacity: 68,46
Number of charge cycles: 11
Manufacture date: 2004-04-15
First use date: 2004-04

...full charge capacity was at about 73Wh before I accidentaly deep-discharged the battery

since then the capacity did not decrease, though...

benz · #6 Post by **benz** » Wed Jul 21, 2004 8:31 am

Model of thinkpad: T42p (2373GVU)
Number of cells: 9
Design capacity: 71.28
Full charge capacity: 72.01
Number of charge cycles: 19
Manufacture Date: 2004-05-17
First use date: 2004-06

andyk · #7 Post by **andyk** » Wed Jul 21, 2004 10:02 am

Model of thinkpad: T42
Number of cells: 6
Design capacity: 47.52
Full charge capacity: 50.27 (why is it higher than 47.52?)
Number of charge cycles: 1
Manufactured date: 6-28-04
First Use Date: 2004-07 (got it yesterday!)

#8 Post by **jdhurst** » Wed Jul 21, 2004 11:42 am

Model of thinkpad: T41
Number of cells: 6
Design capacity: 47.52
Full charge capacity: 43.54
Remaining capacity: 42.42
Number of charge cycles: 14
Manufacturer name: Sanyo
Manufacture date: 2003-12-03
First used date: 2003-12 (post 12-23)
Number of months since the manufactured date: 7

I generally plug in my Laptop when I am using it, although the battery is fine, and I have used it on battery for several long periods. That accounts for the small number of cycles. ... JDHurst

sktn77a · #9 Post by **sktn77a** » Wed Jul 21, 2004 12:05 pm

Maybe this is a dumb question but...... where do you find this information???

Leon · #10 Post by **Leon** » Wed Jul 21, 2004 12:08 pm

plugged in with or witout the batter installed?

I generally plug in my Laptop when I am using it, although the battery is fine, and I have used it on battery for several long periods. That accounts for the small number of cycles. ... JDHurst[/quote]

benz · #11 Post by **benz** » Wed Jul 21, 2004 12:45 pm

Battery Maximiser -> Battery Information -> Information tab

#12 Post by **jdhurst** » Wed Jul 21, 2004 1:17 pm

Keith - Run ThinkPad Configuration under Access IBM or in your System Tray if it's there. Click on System Information, thence on the Battery Information tab.

Leon - I always leave the battery installed. There is no benefit to take it out because most times, it is fully charged and there is no activity.
... JDHurst

sktn77a · #13 Post by **sktn77a** » Wed Jul 21, 2004 6:42 pm

OK, here goes.................

Old Sanyo:
Model of thinkpad: T40
Number of cells: 6
Design capacity: 47.52
Full charge capacity: 37.5
Remaining capacity: 37.5
Number of charge cycles: 11
Manufacturer name: Sanyo
Manufacture date: 2003-06-03
First used date: 2003-08-14
Number of months since the manufactured date:12

New Sony:
Model of thinkpad: T40
Number of cells: 6
Design capacity: 47.52
Full charge capacity: 48.6
Remaining capacity: 48.42
Number of charge cycles: 0
Manufacturer name: Sony
Manufacture date: 2004-05-14
First used date: 2003-07-19
Number of months since the manufactured date: 2

The new Sony still rattles but it looks like I got a new battery after almost a year so I guess I shouldn't complain!

benz · #14 Post by **benz** » Wed Jul 21, 2004 7:41 pm

sktn77a - are you saying youve only been through 11 charge cycles on that battery in 1 YEAR? darn! You must not unplug it from the wall much!

Chun-Yu · #15 Post by **Chun-Yu** » Wed Jul 21, 2004 7:47 pm

Yeah! My T41's 6-cell has had over 90 cycles since last October, and I even have a 9-cell too! (Sorry, no exact figures atm since I don't feel like rebooting into Windows to check, but if I remember correctly my 6-cell is at just under 39 and my 9-cell has about 30 cycles and is at 65.2)

admsteiner · #16 Post by **admsteiner** » Wed Jul 21, 2004 9:12 pm

Thinkpad T42
6 Cell Sony
Design Capacity: 47.52
Full Charge Cap: 48.16
Remaining Cap: 20.15
Number of Cycles: 1
Manufacture Date: 2004-05-13
First Date Used: 2004-07

9 Cell Sony
Design Cap: 71.28
Full Charge Cap: 73.02
Remaining Cap: 55.18
Number of Cycles:0
Manufacture Date: 2004-05-10
First Use Date: 2004-07

--Adam

cjsuh · #17 Post by **cjsuh** » Wed Jul 21, 2004 9:21 pm

Model of thinkpad: T42
Number of cells: 6
Design capacity: 47.52
Full charge capacity: 44.23
Remaining capacity: 44.23
Number of charge cycles: 10
Manufacturer name: Sanyo
Manufacture date: 2004-06-24
First used date: 2004-06
Number of months since the manufactured date: 1

Guess those deep discharges I had really hit my battery hard.

Chatbox · #18 Post by **Chatbox** » Wed Jul 21, 2004 9:29 pm

Here's mine.

Model of ThinkPad: T41p
Number of cells: 9
Design capacity: 71.28Wh
Full charge capacity: 64.99Wh
Number of charge cycles: 15
Manufacturer: Sanyo
Manufacture date: 2004-01-15
First used date: 2004-05

DrBob · #19 Post by **DrBob** » Wed Jul 21, 2004 9:54 pm

Model of thinkpad T41
Number of cells 6
Design capacity 47.52
Full charge capacity 39.03

Number of charge cycles 18
Manufactured date. 2003-10-04 (SONY)
First Use Date 2004-01

Full charge capacity seems to be dropping off but I can still go almost 4hrs on a charge.

Leon · #20 Post by **Leon** » Wed Jul 21, 2004 10:21 pm

Here's an interesting observation... seems batterys are in two classes:

1. Plugged in most of the time; great Full Charge Capacity
2. Deep Discharged (i.e. used on battery power for a long time or often); not so great Full Charge Capacity

So, those who never use/rarely need the great capacity still have it! (But really don't use it or care).

Those who use their batterys a lot/long time lose capacity (but can't do anything about it; that's just the way batterys are)!

So, everybody should be happy! Make sense?

#21 Post by **jdhurst** » Wed Jul 21, 2004 11:41 pm

If you read accurate articles about Lithium-Ion batteries, they all say the same thing: Don't deep discharge a L-I battery. I have an adapter in the car, and I will even plug in there if I have been using the battery. Also when using the battery, I suspend when I don't need it. All in all, I can stretch battery operation over several hours without going below 40 percent or so. By then, I can always find an electric outlet. ... JDHurst

nearly · #22 Post by **nearly** » Sat Jul 24, 2004 1:11 am

THE 6 CELL Sanyo I ordered as an extra with my T42p (9 cell came standard but I prefer the form factor with the smaller battery in place) reports:

Full Charge Capacity 45.47
Design Capacity 47.52

However, after fully charging the battery info icon in the system tray reports charge level at only 58%.

Is this likely to be a faulty battery, or is it just being reported incorrectly?

Chun-Yu · #23 Post by **Chun-Yu** » Sat Jul 24, 2004 12:22 pm

Most likely it is getting confused about the maximum capacity of the battery - did you happen to switch from the 9-cell to the 6 while it was in standby or hibernate? If so, try removing the battery and putting it back in while the ThinkPad is on, then you should see the correct %.

nearly · #24 Post by **nearly** » Sun Jul 25, 2004 12:17 am

Right on the money - I had changed between batteries in hibernate state. Did as you suggested and now reports at 99%. Thanks for that.

Bluecamp · #25 Post by **Bluecamp** » Sun Jul 25, 2004 7:31 am

Leon wrote:Here's an interesting observation... seems batterys are in two classes:

....
2. Deep Discharged (i.e. used on battery power for a long time or often); not so great Full Charge Capacity

....
Those who use their batterys a lot/long time lose capacity (but can't do anything about it; that's just the way batterys are)!

I don't understand your observation. According to IBM's Battery Tips they suggest Deep Discharges for reconditioning the batery power:

"Reconditioning your battery can increase the full charge capacity of your battery. It is recommended that you let the battery run to less than 3% at least once a month.

Occasionally, it may be necessary to "deep cycle" your battery one to three times to give it optimum performance. This will require you to let your battery run completely down, and then to recharge it fully. It is recommended that you charge your ThinkPad overnight for a full charge from a deep recharge condition without leaving your ThinkPad powered on. A brand new battery should be fully charged overnight before its first use. "

Leon · #26 Post by **Leon** » Sun Jul 25, 2004 10:10 am

if this is true, i will stand corrected... however all the info i've seen posted seems to contradict this.... others comments???

#27 Post by **jdhurst** » Sun Jul 25, 2004 10:55 am

I looked up the battery information for my Lithium-Ion laptop battery, and it does not suggest deep discharges. Everywhere I have read about batteries say that deep discharges are not good for L-I batteries.

The advice as posted here is for Ni-MH batteries with a memory.
... JDHurst

nesen · #28 Post by **nesen** » Sun Jul 25, 2004 11:02 am

I would call this Tip a money-maker, the battery manufacturers like it for sure...

As always, google helps here too: http://www.fact-index.com/l/li/lithium_ion_battery.html is just one article out of many.

I think IBM could have been smarter, because it's the only laptop I've seen so far which comes with a Tool to read out the Battery charge amount, therefore making it easy to monitor the max. charge capacity. Without such a tool it would be way harder to verify that the battery charge rapidly decreases with full-discharge cycles.

Bluecamp · #29 Post by **Bluecamp** » Sun Jul 25, 2004 11:09 am

jdhurst wrote: The advice as posted here is for Ni-MH batteries with a memory.
... JDHurst

I look for the information again and found this:

"Perform the following steps if your battery is Li-Ion:

.....Text...Text...Text...

Perform the following steps if your battery is NiMH:

...Text...
"

So they suggest Deep Discharges even for Li-Ion batteries

JMcMasterJ · #30 Post by **JMcMasterJ** » Mon Jul 26, 2004 2:57 am

Model of thinkpad: T42
Number of cells: 6
Design capacity: 47.52
Full charge capacity: 49.61
Number of charge cycles: 4
Manufature date: 2004-06-16
First used date: 2004-06

Full charge capacity vs. Number of charge cycles.

Full charge capacity vs. Number of charge cycles.

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