Battery question

11 posts / 0 new
Last post
KDLST
Offline
Last seen: 6 years 8 months ago
Joined: 12/26/2010 - 08:27
Posts: 226
Location: Belgium
Battery question

Hi fellow babies!

I was wondering about the following... everyone here is saying laptop batteries have 18650's in them... well my batterie is currently dead (lasts about 15 minutes or so...)

Would it be possible to remove the 18650's, buy new ones and then put them in the batterie case? :d

KDLST
Offline
Last seen: 6 years 8 months ago
Joined: 12/26/2010 - 08:27
Posts: 226
Location: Belgium

somehting like this seems good..

anyone has any idea what the difference between dx 18650's and these ones are.? Because they look different..

(and no you fools i'm not talking about the color! Silly )

Budgeteer
Budgeteer's picture
Offline
Last seen: 7 years 11 months ago
Joined: 08/24/2010 - 02:19
Posts: 3087
Location: Slovenia (EU)

Already made packs seems cheap enough not to mess with.

kragmutt wrote:

They're gonna send you a green redcat with a black LED.

Match
Match's picture
Offline
Last seen: 5 years 5 months ago
Joined: 11/14/2010 - 11:57
Posts: 1488
Location: South Carolina, USA

Budgeteer wrote:

Already made packs seems cheap enough not to mess with.

Agreed.  Having taken apart more than a few packs I'll tell you it's not easy. It would involve carefully opening up the case (which is epoxied together), Removing the old cells (which are taped together inside), and soldering the tabs of the new cells correctly and trying to remember where all the balance charging connections need to be landed.  In an emergency it can be done, or if you are unable to source a replacement battery.  But to me it's just a big PITA with a lot of frustration and little to no cost savings.

-Match

Don
Don's picture
Offline
Last seen: 10 months 3 weeks ago
Joined: 01/12/2010 - 16:32
Posts: 6617
Location: Scotland

You may be able to find someone in Belgium who rebuilds laptop battery packs. There are several in the UK. If you have a common laptop it may even be reasonably cheap.

You need specialised equipment to build the packs such as battery welders (Attempts to solder lithium ion cells are very unwise, even dangerous), access to the protection circuits used and so on. And there is no point unless you use good-quality cells, laptops are very, very hard on their cells. It is very unwise to try to do this yourself.

These days a lot of higher-end laptops use specially shaped lithium-polymer packs which are not repairable, just replaceable - in the case of Apple, with one that can only be replaced by the manufacturer.

 

The numbers from my light tests are always to be found here.

https://spreadsheets.google.com/ccc?key=0ApkFM37n_QnRdDU5MDNzOURjYllmZHI...

fishinfool
fishinfool's picture
Offline
Last seen: 2 years 1 month ago
Joined: 03/09/2010 - 00:30
Posts: 4342
Location: Hilo, Hawaii

I've taken apart 3 different laptop battery packs and the li-ion 18650 batteries were pink samsung's, blue lg's and red sanyo's.  I tried to take them apart without breaking anything but it's imposible to do so.  They are glued, taped and soldered together just like Match said but they use some super tough industrial strength/heavy duty glue and tape.  J)

Don wrote:

"But as I said long ago, you are more likely to be killed by a dead fish dropped by a seagull in the Sahara Desert than by a lithium ion

jekostas
Offline
Last seen: 9 years 10 months ago
Joined: 11/30/2010 - 03:09
Posts: 576
Location: Surrey

You're going to need like 8-10 18650s to make up the pack, it's rarely worth it to rip apart a pack to replace them unless you can:

1.  Get them apart without destroying the batteries (which is difficult)

2.  Be sure you're only replacing a few and not all of them (laptop batteries will generally trip a protection circuit if 1-2 fail)

3.  Know which batteries you need to replace and can match the existing batteries in the case in terms of actual mAh rating and output voltage.

 

Otherwise, it's worth it to just get a new battery, unless you can find someone to rebuild it for you on the cheap.  

fishinfool wrote:

I've taken apart 3 different laptop battery packs and the li-ion 18650 batteries were pink samsung's, blue lg's and red sanyo's.  I tried to take them apart without breaking anything but it's imposible to do so.  They are glued, taped and soldered together just like Match said but they use some super tough industrial strength/heavy duty glue and tape.  J)

 

I've actually had very good luck in that regard - I got one of those external laptop battery packs for $15 on sale, took it apart and managed to get 4 (out of 6) good, undestroyed IC protected 2400 mAh Samsungs out of the deal.

Match
Match's picture
Offline
Last seen: 5 years 5 months ago
Joined: 11/14/2010 - 11:57
Posts: 1488
Location: South Carolina, USA

jekostas wrote:

I've actually had very good luck in that regard - I got one of those external laptop battery packs for $15 on sale, took it apart and managed to get 4 (out of 6) good, undestroyed IC protected 2400 mAh Samsungs out of the deal.

I never thought about that as a source.  I've got oodles of unprotected, but if those external packs actually have protected cells in em I'll have to keep an eye out for one.

jekostas
Offline
Last seen: 9 years 10 months ago
Joined: 11/30/2010 - 03:09
Posts: 576
Location: Surrey

Match wrote:

jekostas wrote:

I've actually had very good luck in that regard - I got one of those external laptop battery packs for $15 on sale, took it apart and managed to get 4 (out of 6) good, undestroyed IC protected 2400 mAh Samsungs out of the deal.

I never thought about that as a source.  I've got oodles of unprotected, but if those external packs actually have protected cells in em I'll have to keep an eye out for one.

 

This is the one I bought - http://cgi.ebay.com/iRecharge-Rechargeable-Battery-Laptop-Computers-/320593891813?pt=Laptop_Adapters_Chargers&hash=item4aa4e291e5#ht_5560wt_905

I'm not sure they're available any more as I got mine at a clearance store, but it did provide IC-protected cells.

Match
Match's picture
Offline
Last seen: 5 years 5 months ago
Joined: 11/14/2010 - 11:57
Posts: 1488
Location: South Carolina, USA

Thank you for the link and confirmation on the cells, Jekostas!

fishinfool
fishinfool's picture
Offline
Last seen: 2 years 1 month ago
Joined: 03/09/2010 - 00:30
Posts: 4342
Location: Hilo, Hawaii

jekostas wrote:
I've actually had very good luck in that regard - I got one of those external laptop battery packs for $15 on sale, took it apart and managed to get 4 (out of 6) good, undestroyed IC protected 2400 mAh Samsungs out of the deal.

4 of 6 good and protected?  Lucky you.

Here's something kind of weird.  Last August 8, 2010, when I opened up the battery pack that had 4 red Sanyo 18650’s in it, the first thing I did was to check the voltage.  They were 1.45v, 1.45v, 1.48v and 1.42v which are very bad (from what I have read and learned) for li-ion batteries.  I’ve also read that the best thing is to do is to get rid of them or recycle them because they are pretty much worthless. 

 So of course I went ahead and charged them all up. Undecided  After a full charge they were all around 4.20v/4.21v which was cool but I figured they would lose their charge very quickly after a day or 2.  I am glad to say that I was wrong. Smile  Since then, I’ve checked and logged the voltages about once a month and today, after almost 5 months, the voltages are 4.14v, 4.15v, 4.15v, and 4.14v. 

 So what gives?  Is this normal?  Did I just get lucky? 

 Inquiring minds wanna know.

 

Don wrote:

"But as I said long ago, you are more likely to be killed by a dead fish dropped by a seagull in the Sahara Desert than by a lithium ion