latop battery unit

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kasar
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latop battery unit

Post by kasar » Sat Jan 26, 2008 8:39 am

hi guys, I finally take the photos of the battery mod, but before post nothing at the news zone, I want be sure about the mod sucess.

after the mod I experienced some fixes like:

* fixed battery jump from 47% to the 3% on windows battery monitor.

* before it was arround 40 mins of life, now it is about 2X before



I know you are thinking about why I posted this if the mod enchanced the battery duration and battery monitor precision. but I think maybe i can get more time, for example, i think the battery circuit board is designed to 8 cells only and not to 12 (I saw on internet another pack with more AH than the default, IT should have 12 cells and a different circuit board) I only modified the number of cells, but the circuit board is not modified. (And I think I will not able to do it with my cuarent skills)

the question is: when the board detects the aH for the 8 default cells is full, it stop charging or it still untin all cells get fully charged???

actually I also have some software who get info from the battery board, and the software says it still have 8 cells and the battery model.

but I noticed the working time of the battery pack increased since the mod.

I think that maybe the new cells get charged a few due the old cells lost some charge capacity instead of the entire cells being charged fully.


Some one can help me with this? I´m not sure about this.


OH I forgot. here are the mod details:

this is the battery

Image

this photo is after the mod, but I made pic of the old allocation


Image
pic here:
Image


you can see it have only the 8 default cells

and the battery should be 14.8V and 4000mAH
is normal the get 16,5 volts instead 14,8 from the internal battery poles?


well after the mod

Image
Image

and the pic

Image


as you can see I aded more 4,7 cells (4 more) so I got a total of 12 cells inside the battery box,I connected all the cables to get like the default 8 cells.

is the Mod ok?

I think the green, yellow and the gray cables are for allow the battery board get the cuarent charge values from the individual cells, but I´m not sure. anyway I connected them like the 8 default cells adding also a conection for the 4 new ones cells.

the new cells aren´t new, I got them from a broken latop I have at home.


I checked the "new" batteryes (orange cells) the name is cgr18650hg

http://www.206xs.com/topics/battery/Pan ... 8650HG.pdf

as you can see It have:
3,6volts
1800m


the default ones (blue) ICR18650-22b

http://www.akkushop-online.de/Industrie ... :1748.html

3.7v
2200mAH

I know is not very recomended join diferent cells, but I have now low money and a lot of broken latops at home, so I made this.

I also found two battery models for the Travelmate 240 battery packs

http://www.batteryfast.com/acer/btp-58a1.php

the 4400 mAH (the one I have)

and this one

the 6600 mAH

watching the cuarent cells in my mod I calculate this:

2200 + 2200 + 1800 = 6200 mAH on my mod

but I´m not sure about this will be so easly

can someone ask some of my questions??

I´m very confused.

thanks for your help again.

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Post by jaimegmr » Sat Jan 26, 2008 4:24 pm

Im not sure, but I think that by putting in different capacity batteries, you could possibly be overcharging the lower capacity cells since the circuitry was made for the higher capacity cells. Hopefully you dont come back and post about your battery pack overheating and exploding. I would just spend some money on cells of greater than or equal capacity to the original cells. (Best way to go would be to replace all the cells)

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Post by kasar » Sat Jan 26, 2008 7:26 pm

jaimegmr wrote:Im not sure, but I think that by putting in different capacity batteries, you could possibly be overcharging the lower capacity cells since the circuitry was made for the higher capacity cells. Hopefully you dont come back and post about your battery pack overheating and exploding. I would just spend some money on cells of greater than or equal capacity to the original cells. (Best way to go would be to replace all the cells)
uhh what?

I think that could happen If I replace the default ones by a lower capacity, but I didn´t, I only aded extra cells without remove any of the old cells(before was a emty space in the cuarent new cells space), I think the old cells should be recharged like before, and the new cells should get a little charge from the defaults cells. but this is only my theory, So I´m not sure.

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Post by nitro2k01 » Sun Jan 27, 2008 6:29 pm

A word of caution: LiIon batteries are sensitive to over-charing as well as under-charging. If you over-charge a Li-Ion battery it will explode/leak. If you drain a Li-Ion battery under a certain voltage, and then recharge it, it will also explode/leak. The battery charging circuit protects the cells from these phenomena. But maybe the protection against under-charging will not work correctly with your new cells, since they are rated at a little higher voltage.

My suggestion. Turn off alarm actions in Windows (Control Panel>Power Options>Alarms>Uncheck both actions) Drain the battery completely (Disconnect the AC adapter and put on a CPU intensive task to make it happen faster) At this point the computer will not enter suspend mode, but it will turn itself off hard, since the power is drained.
When the battery is drained, recharge it and monitor it closely for any problems and immediately rip out the battery cord if you see or hear anything suspicious.
When the battery is full again, repeat the process. If you've done this twice, and the battery cells don't show any signs of problems, it's probably ok.
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Post by timmeh87 » Mon Jan 28, 2008 11:20 am

bad bad bad bad bad

dont put cells of different capacity in parallel. The older ones will discharge faster, then the newer ones will start to charge them. it just bad times. If you are lucky maybe some of them will explode.

These lithium batteries have circuits that estimateshould work just fine.
capacity by measuring the total current (instead of cheaper ones which just measure voltage). once it "learns" a new capacity (sometimes need to hit a button in software or something, to allow it to drain all the way to 0%), it should work just fine.

Also, 4.2v per cell is normal on a full charge.
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Post by kasar » Mon Jan 28, 2008 5:19 pm

nitro2k01 wrote:A word of caution: LiIon batteries are sensitive to over-charing as well as under-charging. If you over-charge a Li-Ion battery it will explode/leak. If you drain a Li-Ion battery under a certain voltage, and then recharge it, it will also explode/leak. The battery charging circuit protects the cells from these phenomena. But maybe the protection against under-charging will not work correctly with your new cells, since they are rated at a little higher voltage.

My suggestion. Turn off alarm actions in Windows (Control Panel>Power Options>Alarms>Uncheck both actions) Drain the battery completely (Disconnect the AC adapter and put on a CPU intensive task to make it happen faster) At this point the computer will not enter suspend mode, but it will turn itself off hard, since the power is drained.
When the battery is drained, recharge it and monitor it closely for any problems and immediately rip out the battery cord if you see or hear anything suspicious.
When the battery is full again, repeat the process. If you've done this twice, and the battery cells don't show any signs of problems, it's probably ok.
I did this a few days ago arround 5 times and now problems detected.
I also have the suspend modes off, my windows only notice me about the battery status , but it doesn´t shut down or suspend automatic,the latop screen swvel is also setup for "do nothing when the case is close" I allways like to use the max battery posible and still have the running process
timmeh87 wrote:bad bad bad bad bad

dont put cells of different capacity in parallel. The older ones will discharge faster, then the newer ones will start to charge them. it just bad times. If you are lucky maybe some of them will explode.

These lithium batteries have circuits that estimateshould work just fine.
capacity by measuring the total current (instead of cheaper ones which just measure voltage). once it "learns" a new capacity (sometimes need to hit a button in software or something, to allow it to drain all the way to 0%), it should work just fine.
:shock: hell damnit
oops, that is right, I will change the cells as soon as posible, thx.

I also have a question, the default 8 cells are 2200 mAH

will I get extra charge if I put 12 cells (4 + 4 +4 paralel) of higher mAH, like 2800mAH?

or will the protect circuit limit them only to 2200mAH per cell?

thx a lot for your answers guys, it helped me a lot.

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Post by timmeh87 » Mon Jan 28, 2008 11:11 pm

Im pretty sure it should adjust itself to the new capacity.

Of course, it might have a maximum size before some variable in memory overflows, etc..

They will adjust down as the battery gets old, so I dont see why it wouldn't adjust up as high as it needs to as well.
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Post by kasar » Tue Jan 29, 2008 10:20 am

timmeh87 wrote:Im pretty sure it should adjust itself to the new capacity.

Of course, it might have a maximum size before some variable in memory overflows, etc..

They will adjust down as the battery gets old, so I dont see why it wouldn't adjust up as high as it needs to as well.
ty.

hey guys I was wrong about the battery Volts, my pics ask bout 4,7 but the correct value per cell is 3,6v - 3,7v , I wrote it wrong due a incorrect polimeter medition.


I found some great mAH battery

http://www.onlybatteries.com/showitem.a ... 7&uid=1107

I want 12 cells for make a great battery (2600 mAH :D I cant found higher mAH ones)

+- +- +- +-
+- +- +- +-
+- +- +- +-

but this cells cost a lot...

12 units x 13.89$ = I can´t pay them :evil:

I made another 5 full discharge - full charge tests and no problems detected. so I think my house will not burn in flames I think


someone know any cheaper site for get some cells at a fine price?

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Post by timmeh87 » Tue Jan 29, 2008 11:44 pm

Those 2600mAh 18650 cells you are looking at are top of the line stuff. They are a very common kind of cell for this application, and they come in sizes of 2000, 2200, 2400, and just recently, 2600. It seems that they release a bigger size about every year or so. My 4-year old laptop had 2000's in it.

Anyways you arent going to find 2600s for much cheaper, thats about market price, always has been for the new stuff. A few years ago you had to pay that much for some 2200's. Luckily, now they are only $7 per cell over at www.batteryspace.com.

http://www.batteryspace.com/index.asp?P ... tegory=739
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Post by kasar » Wed Jan 30, 2008 3:07 pm

hey thanks for the links timmeh87!

yes , you have the point,I cheked the links and there aren´t a lot of diference betwen the 2600 mah cells (1$ diference), those batterys are a little expensive,anyway I need reload a bit my pocket before buy anything (IT is actually emty :S)

but I´m also very satisfated guys with all the replies I had on this post,It helped me a lot to fix my little confusion :lol: .

I think that the sites like this helps a lot internet to become a more bigger and friendly thing.

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