mookaloid
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| posted on 17/4/08 at 11:06 AM |
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Laptop battery
Is it possible to replace the cells in my laptop battery which seems to be dead, or is this a bad idea?
Cheers
Mark
"That thing you're thinking - it wont be that."
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blakep82
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| posted on 17/4/08 at 11:07 AM |
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http://www.battech.co.uk/
i'd just have a look here ^
________________________
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don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
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mookaloid
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| posted on 17/4/08 at 11:13 AM |
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Mmmmm quite pricey there - I was wondering if I could get some cells from Maplins and replace the Bu**ered ones in my battery pack.
Something like these mind you I have no idea how
many are inside the pack 
Cheers
Mark
"That thing you're thinking - it wont be that."
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blakep82
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| posted on 17/4/08 at 11:19 AM |
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personally i wouldn't 
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
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Mr Whippy
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| posted on 17/4/08 at 11:23 AM |
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If you look on the web for model car battery packs there are small companies who will make up packs to you exact requirements. Soldering the tags on
requires a large soldering iron so the solder melts as quick as possible rather than prolonged heat from a smaller iron that would end up cooking the
cell.
[Edited on 17/4/08 by Mr Whippy]
Fame is when your old car is plastered all over the internet
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Dickyboy
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| posted on 17/4/08 at 12:15 PM |
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Depends if they are NiCd, NiMh or LiPo, NiCd and NiMh are comparatively safe, unless you short them out. As long as the soldering is up to scratch and
the insulation sound should be fine. Lithium Polymer is a different subject, the charging and discharging is critical, overcharge and you may end up
with a fire that is almost unextinguishable, like wise for discharging, they are usually in a "soft" pack making damage easier, most have
extra leads to monitor the charge per cell, so is a lot more complex, this is all from model aircraft experience, but the batteries are still the same
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02GF74
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| posted on 17/4/08 at 12:23 PM |
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I looked into doing this for a B&D drill that but for the same cost, I could get a new drill....
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tks
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| posted on 17/4/08 at 12:34 PM |
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ebay has moste of the time compatible battertyes for your laptop, pda,phone etc, etc,
Tks
The above comments are always meant to be from the above persons perspective.
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r1_pete
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| posted on 17/4/08 at 02:54 PM |
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You still on the T41 Mark? if so I have a good battery in my old business lappy could do a swap if you want....
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MikeRJ
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| posted on 21/4/08 at 09:11 AM |
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You can replace the cells, the issues are as follows:
1) Getting new cells. Most modern laptops use 18650 cylindrical cells, some of the older ones (esp. Toshiba) use a flat shaped cell. Maplin
don't sell them, and getting new cells separately in the UK can be difficult. You should replace all the cells (unless you have facilities for
checking cell capacity and matching them), and the cells must all be of the same capacity.
2) Getting the battery apart. They are welded together, some of the them can be absolute barstewards to take apart. This is made more difficult by
having to keep the case as intact as possible. If you mangle it it won't go back together.
3) Replacing the cells. Cell connections are always spot welded. Separating the cells from the bus without damage to the later is important, usually
you can tear the tag off the top of the cell with a pair of needle nose pliers. As long as you get cells with tags on the end they can be soldered
back in, but never solder to untagged cells.
A bigger problem is the protection circuit. Many laptop batteries die completely and suddenly if left too long. The reason for this is that once the
cell voltage degrades too far, they can become dangerous to recharge, so the protection circuit in the pack will detect this condition and blow an
internal fuse rending the battery useless. If this hasn't already happened, then messing around with the pack without disabling the protection
circuit is likely to make it happen.
4) Getting the battery assembled again. As long as you got it apart without mangling the plastic case this shouldn't be too bad.
I've rebuilt a few packs using cells I have salvaged from other dead packs and checked for balance (handy if you know an IT guy at work).
It's a very labour intensive operation, and one slip of the soldering iron or a screwdriver etc. can short the power bus and write the whole
thing off in seconds.
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