Identifying the 18650 battery pulled from T61P

Hi.

I have pulled 18650 cells from a T61P Lenovo, or IBM if you prefer, laptop. After taking off the coat I am left with meaningless - at least to google and me - two set of digits:

1)0KMM4ID
2)076265

My aim is to identify the capacity of that cell. I am working onto replacing the cells in battery pack for longer battery life - although I am not sure if it is even worth it. Depends on properties of this cell. So, the first question is if you are able to identify this tricky cell?

Regards,
eru3

It is also worth to note, that at the bottom there is third set of "digits"(sorry, I have mistaken the word in previous post): 60KMN1. Is there any way to edit previous posts?

Welcome to CPF, eru3!

Usually you can deduce (new) capacity for the cells used, by looking at voltage & Ah for the entire pack, combined with how many cells are in there. There's only so many ways to wire a small number of cells in series or parallel...

So: how many cells did you find inside? And what's the voltage / Ah rating of that battery pack?

Note that a laptop battery pack will have a battery management circuit inside, and it may not like / get confused / refuse to 'adopt' new cells if you drop those in. Sometimes there may be a way to reset that management circuit, sometimes not. Given the price of a replacement battery pack, buying a replacement set of cells in the hope that dropping them in will work, seems like a big gamble...

Post pictures of your cells.

Chris

Yeah, by calculation I assume 2600mAh for one. Although such a pack costs 12 pounds on Ebay for new battery - would thet be even possible for it to have such specification

It is 12.6V for 3 in series x3(9 cellls all together)

I will post photos soon, sorry for the delay. The claimed powerhours of battery pack is 75-79Wh.

eru3 said:

Yeah, by calculation I assume 2600mAh for one. Although such a pack costs 12 pounds on Ebay for new battery - would thet be even possible for it to have such specification

It is 12.6V for 3 in series x3(9 cellls all together)

I will post photos soon, sorry for the delay. The claimed powerhours of battery pack is 75-79Wh.

Click to expand...

is 12.6V what you measured or got from the specs on the battery pack? Generally the voltage will be 10.8 or 11.1 for 3 in series, for 3.6V or 3.7V 18650's. 12.6V is the fully charged state.

In any case, I think you have a 10.8V 7200mAh pack looking through the collection of the ones I have, so 9 cells, 3S3P, 2400mAh per cell.

If the wrapper is orange, then it is an aftermarket cell from a Chinese factory. Second number is most likely a serial number, you can check as it should be different on each 18650. If the wrapper was red, then you could be in luck and have got a Sanyo but the markings don't seem to be Sanyo. There will be a four character alphanumeric code which is the manufacturing date if it is a genuine Sanyo.

Let me put it this way. Battery pack claims: 10.8V and 7,2Ah. However the measured voltage on quite charged cells is coming as 12.6V. Some voltage must be taken by the electronics inside the battery and that has to be the magic voltage drop. Now the calculations:

Laptop consumes 20-25W during the normal usage. Let us assume for the average of the whole consumption to be 25W.

25/10.8= 2.31A consumed at the battery.
7,2Ah/2.31A=3,12 hours of battery time - that is correct with my observations of my battery life. We did not count for the electronics, as I have no clue about it power consumption. Should be so little, it doesnt matter. Now the Ah of one battery, which I am not sure if it is correct.

Batteries in series acumulate voltage, while decrease capacitance. It evolves that 3 same cells, connected in series, have 3x voltage of one cell and capacitance of one cell. Therefore 3 parallel-3series pack would give us 7200:3=2400mAh(I have made a memory mistake in the previous post). Now, the question is if I am right? After all you are the masters of batteries.

This seems to be Sanyo battery pack, have a look:


The battery pack photos:



Sorry about the size and quality, but spoiler tags do not work(?). Also, it is an HTC M9 - here you see how bad is the camera software The whole point of this is to answer the question is it worth to swap batteries for the famous Panasonic, in terms of:

1. Battery Life.
2. Device's health(I want this laptop to serve me for next 5 years).
3. Cost effective.

Thanks a lot for answers and sorry for delay in answering - busy life or lack of organisation

Such battery pack cost 12 pounds for a new one. I find it hard to believe, that good batteries would be sold in that.

eru3 said:

Such battery pack cost 12 pounds for a new one. I find it hard to believe, that good batteries would be sold in that.

Click to expand...

12 pounds on Ebay is not likely to give you a "new" one. Even if it hasn't been used (and I wouldn't count on that either) it might be so cheap because it is excess inventory, and has been sitting unsold for years. Lithium-ion cells decline over time, whether you use them or not, and storing at full charge or high temperatures will greatly accelerate that degradation. You won't know for sure about the performance until you try it, and it might be worth the cost savings, but don't expect a miracle for that price.

I have never bellieved such a thing. This is why the thread was created - to determine specification, age and need/possibilty of upgrade the cells to Panasonic NCR18650B. Pricey is the least, battery life the most. Somewhere in between sits the care for steady supply to laptop, so it can function longer maintaining high comfort of use.

They sell them on Ebay as new, they seem to be unopened and deisgned capacity almost meets the real capacity of cells. So either they decay slowly while being stored for long time, or perhaps Lenovo sells them at a fixed price to get rid off the stock? I guess there are not too many owners of T61/T61P laptops compared to new devices.

I'll chime in here because I've got a T61 as well. I think much of the info is already in the screenshot you posted. The designed capacity is 71280 mWh, which is 71.28 Wh. Since you stated the voltage is 10.8 V, the amperage must be 71.28 / 10.8 = 6.6 Ah. Is this a 9-cell or a 6-cell pack? (The 9-cell stands out from the backside of the laptop while the 6-cell one doesn't... unless it's a completely different model) With a 9-cell pack, each cell should have 2.2 Ah, while with a 6-cell pack, each cell should have 3.3 Ah. This puzzles me a bit because both the original and the replacement pack on my T61 have 2.6 Ah on the cells.

The 12.505 V measured in the screenshot (in fact it never charges to a full 12.6 V as far as I know) is the fully charged, unloaded voltage of the pack. The voltage sags when the pack is being loaded, and it also goes down during the discharge, although the 10.8 V is rather at the lower end of the discharge curve... during my last calibration it was reached at a charge level of about 14% (calculated value).

The age info should actually be in the pack... apparently your system information doesn't put it out, but you should be able to download a battery manager software which will give you that info (when the pack has been manufactured and first used), as well as the number of cycles the pack has gone through (however, Lenovo counts a 70% discharge at 1 cycle! And I don't know if this piece of software will run on Windows 10...).

Have you ever tried to calibrate your battery? According to your screenshot, it should still have 89.6% of its original capacity, however this may be only an estimate if the battery never gets completely discharged. The actual capacity may be more or less than that. As it seems, this also depends on the behavior of the pack, and since you have a different pack than me, I don't know how yours estimates the remaining capacity, but it may well be that on calibrating it, you get back most of the capacity you've lost so far since the capacity loss has been overestimated. However, it may also have been misunderestimated if the pack never updates its remaining capacity (which happened with my original pack which hadn't been used much by the original owner).

Oh, and thank you for confirming you can run Windows 10 on that thing... this means I won't have to give it up for a long time to come. ;-)

I am glad to make you happy seeing T61P running Windows 10. Guess what, performance and drivers are all fine! Literally every single driver works(except Sinaptics, but there is a way around it and issue is on their side; I am talking about unofficial Lenovo one - enabling multitouch gestures).

My pack is 9-cell pack, 10.8V is rather the low charge thing, aye. I did measure the voltage with proper multimeter and it shows up as 12.6V at charged battery too. I have never calibrated this one, I believe it is done by Windows itself, but it could be wrong. I will try to download the mentioned software to check upon cycle rates and calibrate it. Also:

My pack claims to be 10.8V and 7200mAh. Anyway, would it be worth to replace the cells for 3400mAh(Panasonic Green Hero of Candle Power Forums, all hail to Panasonic)?

I don't know if it would make sense to replace it... are you dissatisfied with the runtime you get at the moment?

I don't think Windows itself calibrates the battery... at least not intentionally. It may readjust by itself if you run down the battery completely or charge it to 100%, however I'm not sure about that. A proper recalibration consists of fully charging the battery, then discharging it in one session and then fully charging it again. The battery / management electronics / software should have a mode where it does this even though it's running on AC power... however Windows would never initiate such a recalibration by itself because you should let the laptop alone while it does this for some hours, at most it will recommend recalibration, but it never did this for me although I only recalibrate my pack about every 8 months.

The 7200 mAh sound a bit fishy to me... according to your screenshot it's only 6600 mAh, so 2200 mAh per cell. In this case, the Panasonic cells would give you 3400 mAh instead of 2200, so more than 50% more. I think you will get away with installing them in the pack if you do it properly, however, you will have to recalibrate it in order to have it recognize the bigger capacity. But even if you don't do this, you will probably still be able to use the full capacity, only your battery meter will be off.

Someone at Amazon tested this (or a similar) cell, and after 299 cycles, it had degraded to about 69% of its rated capacity. Is that what you want? How many cycles per year are you putting the battery through? You can try to slow down the degradation by setting the system so it doesn't charge the battery to 100% each time. This should greatly help with longevity because most of the degradation occurs when charging to a high level. I've set my T61 so it only charges the battery to 85%, which is the level the Chevrolet Volt charges its traction battery to. However, the T61 will still charge to 100% every now and then because of calibration errors. I've now put my battery through 364 cycles in 3 years (as counted by the system), and it's lost only about 15% of its rated capacity although the laptop is running through my entire workday (mainly on AC).

I want moaaaaahr capacity!!

I would like to get 5 hours of this laptop without extensive power saving. Right now at high performance it is 3 hours 10-20 minutes. Our disagreement on the capacity of battery comes due to one talking about designed, other one about current(given calibration is fine). I am just comparing against designed, as these cells could be bought for 12 pounds only. So for me it is checking against them if it is worth to create one or two with better cells to notice a massive improvement

Let me download Lenovo stuff, let's see through how many cycles this battery was put.

BTW I got LED mod too, so it affects the amount of energy laptop consumes.

Naaah, I cannot get full utility to run, only the service. Other programs do not provide the info on number of cycles. I can measure the consumption of laptop from the power supply I have - it will show me the current going into the laptop.Although I think it is not necessary. Question is the Panasonic's batteries

To make it even more demanding - I am planning onto fitting the Quad Core(QX9300) in that laptop. To get 5 hours of that even with frequency/a lot of voltage decrease will be a challenge.

eru3 said:

Naaah, I cannot get full utility to run, only the service. Other programs do not provide the info on number of cycles. I can measure the consumption of laptop from the power supply I have - it will show me the current going into the laptop.Although I think it is not necessary. Question is the Panasonic's batteries

Click to expand...

What kind of difficulties do you get with the full utility? That one should be called PowerManager, I don't know which version is current, but I can recall I had a problem when I tried to install the current version of it on my laptop... it crashed on startup 50% of the time. I'm running XP though, don't know how it behaves on Windows 10. My solution was to find an old version of PowerManager which runs flawlessly (at least on XP). The one I got is version 1.88 which is for Windows XP and doesn't require a .net framework as the newer versions do. Google up "Lenovo power manager 1.88" to find it. I don't know how well it works on subsequent Windows versions though... but it might as well give you less problems than the current version.

It does not start. The service is within the Windows and starts. But utility itself never starts, even in compatibility mode. Version is the newest one for Windows 7 from Lenovo website - 1.87.

eru3 said:

It does not start. The service is within the Windows and starts. But utility itself never starts, even in compatibility mode. Version is the newest one for Windows 7 from Lenovo website - 1.87.

Click to expand...

1.87? That's not the newest one by far, it's even older than mine (1.88). Maybe you got the wrong version... look here:

https://support.lenovo.com/us/en/pr...ies-laptops/thinkpad-t61p//downloads/DS014924

This should give you version 6.67.4, which would be the newest version that runs on T61P's. The version number of the download might be different to that of the actual driver, but I doubt that.

This one complains that it cannot run on this system. Any good third party software? It would have to be for Windows 8 at least to run it here, I guess.

Well, I don't have any experience with third-party software for battery management since PowerManager works for me (on Windows XP). Note that the version you downloaded does run on Windows 7 (and maybe even on Windows 8), but it doesn't seem to work on Windows 10.

However, I've found something you could try to at least get some additional data about your battery...

http://www.helpwithwindows.com/Windows8/Windows-8-Check-Your-Mobile-Device-Battery-Health.html

I suppose this command will also work on Windows 10...
There also seems to be a manual way of doing the recalibration...

http://forum.notebookreview.com/threads/any-good-battery-re-calibration-software.513838/

There is one third-party software I found, but I don't know if it's able to do the recalibration automatically...

http://batterybarpro.com/

And here is a description how to change the registry settings if the battery shouldn't be fully charged every time...

https://forums.lenovo.com/t5/Window...ThinkPads-under-Windows-8-without/td-p/916361

I know it's all a bit complicated without PowerManager. There's another version of PowerManager where they have done some support for Windows 10, but it doesn't seem to run on a T61 or T61P, or at least hasn't been tested on it, but maybe it does run on your machine:

https://support.lenovo.com/us/en/downloads/migr-70967

Newest Power Manager works, but it relly does not give me any option I did not have before Powercfg -batteryreport does not work due to "old hardware", but I personally think that it is due to specific design of Thinkpads. Even on Linux if you have Thinkpad, you have to download additional repositories and other things to make it work. So...

I have found the cells. Their capacity is 2600mAh, probably around 200mAh*1.8V=0.36Wh for the electronics. Which is most likely a bit less in real life. So this leaves me with 2400mAh capcity and decreasing as this battery pack has came with this laptop, so it was used by someone else too. Now:

http://budgetlightforum.com/node/13561

http://www.dx.com/p/genuine-sanyo-18650-2600mah-rechargeable-battery-red-pair-121445#.VU9XYhXNnP4

http://www.candlepowerforums.com/vb/showthread.php?344741-Test-Review-of-Sanyo-18650-2600mAh-(Red)

http://www.batteryonestop.com/baotongusa/products/datasheets/li-ion/sanyo-ur18650f-26a.pdf - the most important one

I got the information I wanted... Now I think will be the time to think about cell swapping for this battery pack. To gain 800mAh in each series, so 2400mAh all together(3 rows) that is equal to 10.8*2.4=25.92Wh. More or less another hour for my device. Unless there are any cells like Panasonics(top end) with very low internal resistance compared to Sanyo cells? Than, more power would be transfered to cells. Any ideas?

More or less the properties of desired cell:

* 3400mAh capacity
* Protected(but do not have to be)
* Can drive up to 6-8A current
* low internal resistance(lower than 0.1 preferably)
*18650

You have to be very careful swapping the cells. If the BMS detects any anamolous events then it may permanently disable itself (e.g. blow a hard fuse). This usually means that you need to keep the BMS alive during the open-pack surgery. Once the BMS loses power you cannot reboot it without a proprietary password and software (except for very old BMS boards).