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li-on battery replacement/repair

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Anonymous
a b D Laptop
August 28, 2004 5:35:18 PM

Archived from groups: comp.sys.laptops (More info?)

Is it possible to repair a Li-on battery. Replacements for my old
Fujitsu seem to be very costly($200US PLUS). Can these be restuffed
with less costly NiMH batteries? My battery will not take a charge at
all and is completely dead.
mi-oldradios
Anonymous
a b D Laptop
August 28, 2004 6:15:19 PM

Archived from groups: comp.sys.laptops (More info?)

mi-oldradios wrote:
> Is it possible to repair a Li-on battery. Replacements for my old
> Fujitsu seem to be very costly($200US PLUS). Can these be restuffed
> with less costly NiMH batteries? My battery will not take a charge at
> all and is completely dead.
> mi-oldradios

It would be a bad idea to use NiMH in there, but you can get bare LiIon
cells for much cheaper than a branded battery pack. You have to be handy
at soldering to repair it yourself though. I've replaced the dead
batteries in a number of my Sony Vaio packs. Most of them work fine, but
I screwed up one pack and it stopped working, even with fresh batteries.
You have to be careful not to fry the control electronics in the pack...

One of the nice things about rebuilding Vaio packs (BP71, BP2E) is that
the batteries available today are higher capacity than the ones Sony
used. I can get 10-30% more runtime than the stock batteries now, as
well as saving 50-75% of the cost. www.sabahoceanic.com sells the bare
cells, and they'll attach solder tabs for you too, making the repair
pretty simple. Sabah also sells full packs for a variety of notebooks,
but you can still get higher capacity and cheaper cost using their bare
cells and rebuilding your own.

Another trick I've used to avoid some of the risk of soldering is to use
copper foil tape. It conducts very well, usually stays put, and there's
no heat issues. I've used this approach for all my recent rebuilds, and
haven't destroyed any control circuits since then.

It's also good to have a decent voltmeter handy so you can verify your
pack's internal circuit layout. You might need a LiIon charger if the
pack doesn't reset itself automatically, I use a Maha 777 II+.
--
-- Howard Chu
Chief Architect, Symas Corp. Director, Highland Sun
http://www.symas.com http://highlandsun.com/hyc
Symas: Premier OpenSource Development and Support
Anonymous
a b D Laptop
August 29, 2004 4:09:03 AM

Archived from groups: comp.sys.laptops (More info?)

You can't change the battery SYSTEM (NiMH to LiIon), and you can't
easily or safely replace LiIon cells.

After you replace the battery, don't leave the battery in the laptop
when running on AC power for long periods of time.


mi-oldradios wrote:

> Is it possible to repair a Li-on battery. Replacements for my old
> Fujitsu seem to be very costly($200US PLUS). Can these be restuffed
> with less costly NiMH batteries? My battery will not take a charge at
> all and is completely dead.
> mi-oldradios
Related resources
Can't find your answer ? Ask !
August 29, 2004 4:09:04 AM

Archived from groups: comp.sys.laptops (More info?)

Barry Watzman wrote:
> You can't change the battery SYSTEM (NiMH to LiIon), and you can't
> easily or safely replace LiIon cells.
>

There was a period of time during the transition from NiMH to LiON
where laptops supported both chemistries. But the internal workings of
the battery were different. No you can't just replace the cells,
but if you did find a REAL NiMH version for your system, you might be
able to determine
where to connect the thermistor and sense pins and reuse your
LiON plastic parts as a NiMH pack, sometimes, maybe, wear safety
glasses, don't try this at home...

General rule of thumb.
Always buy used laptops with good batteries.
When the battery goes flat, buy another used laptop.
mike


--
Return address is VALID.
Wanted, 12.1" LCD for Gateway Solo 5300. Samsung LT121SU-121
Bunch of stuff For Sale and Wanted at the link below.
Compaq Aero floppy,ram,battery.
MINT HP-41CV, 2-METER AMPS, 200CH SCANNER
http://www.geocities.com/SiliconValley/Monitor/4710/
Anonymous
a b D Laptop
August 29, 2004 4:10:23 AM

Archived from groups: comp.sys.laptops (More info?)

There are two problems with this:

1. Unless the new cells EXACTLY match the old cells, there is a very
real fire/explosion hazard. People have been killed and/or lost limbs
because of improper lithium batteries.

2. Almost all laptop LiIon batteries have internal microprocessors that
control charging. These have a "memory" (literally", and once they have
determined that the battery is bad, they won't let you charge it even if
you do replace the cells with good ones. In a very few cases, there is
a program to reset these. In a very few other cases, very complex
"hacks" have been devised to accomplish the same thing. But in almost
all cases, there's nothing that the end-user can do to reset the battery
controller.


Howard Chu wrote:

> mi-oldradios wrote:
>
>> Is it possible to repair a Li-on battery. Replacements for my old
>> Fujitsu seem to be very costly($200US PLUS). Can these be restuffed
>> with less costly NiMH batteries? My battery will not take a charge at
>> all and is completely dead.
>> mi-oldradios
>
>
> It would be a bad idea to use NiMH in there, but you can get bare LiIon
> cells for much cheaper than a branded battery pack. You have to be handy
> at soldering to repair it yourself though. I've replaced the dead
> batteries in a number of my Sony Vaio packs. Most of them work fine, but
> I screwed up one pack and it stopped working, even with fresh batteries.
> You have to be careful not to fry the control electronics in the pack...
>
> One of the nice things about rebuilding Vaio packs (BP71, BP2E) is that
> the batteries available today are higher capacity than the ones Sony
> used. I can get 10-30% more runtime than the stock batteries now, as
> well as saving 50-75% of the cost. www.sabahoceanic.com sells the bare
> cells, and they'll attach solder tabs for you too, making the repair
> pretty simple. Sabah also sells full packs for a variety of notebooks,
> but you can still get higher capacity and cheaper cost using their bare
> cells and rebuilding your own.
>
> Another trick I've used to avoid some of the risk of soldering is to use
> copper foil tape. It conducts very well, usually stays put, and there's
> no heat issues. I've used this approach for all my recent rebuilds, and
> haven't destroyed any control circuits since then.
>
> It's also good to have a decent voltmeter handy so you can verify your
> pack's internal circuit layout. You might need a LiIon charger if the
> pack doesn't reset itself automatically, I use a Maha 777 II+.
August 29, 2004 4:10:24 AM

Archived from groups: comp.sys.laptops (More info?)

Barry Watzman wrote:
> There are two problems with this:
>
> 1. Unless the new cells EXACTLY match the old cells, there is a very
> real fire/explosion hazard. People have been killed and/or lost limbs
> because of improper lithium batteries.
>
> 2. Almost all laptop LiIon batteries have internal microprocessors that
> control charging. These have a "memory" (literally", and once they have
> determined that the battery is bad, they won't let you charge it even if
> you do replace the cells with good ones. In a very few cases, there is
> a program to reset these. In a very few other cases, very complex
> "hacks" have been devised to accomplish the same thing. But in almost
> all cases, there's nothing that the end-user can do to reset the battery
> controller.
>
great, can you provide links or other information on resetting battery packs
in cases where some information is known.
Thanks, mike



--
Return address is VALID.
Wanted, 12.1" LCD for Gateway Solo 5300. Samsung LT121SU-121
Bunch of stuff For Sale and Wanted at the link below.
Compaq Aero floppy,ram,battery.
MINT HP-41CV, 2-METER AMPS, 200CH SCANNER
http://www.geocities.com/SiliconValley/Monitor/4710/
Anonymous
a b D Laptop
August 29, 2004 8:56:57 PM

Archived from groups: comp.sys.laptops (More info?)

No, I can't, although I've seen this information on the web for some
Compaq models. You will have to do a web search, the information varies
by battery type.


mike wrote:

> Barry Watzman wrote:
>
>> There are two problems with this:
>>
>> 1. Unless the new cells EXACTLY match the old cells, there is a very
>> real fire/explosion hazard. People have been killed and/or lost limbs
>> because of improper lithium batteries.
>>
>> 2. Almost all laptop LiIon batteries have internal microprocessors
>> that control charging. These have a "memory" (literally", and once
>> they have determined that the battery is bad, they won't let you
>> charge it even if you do replace the cells with good ones. In a very
>> few cases, there is a program to reset these. In a very few other
>> cases, very complex "hacks" have been devised to accomplish the same
>> thing. But in almost all cases, there's nothing that the end-user can
>> do to reset the battery controller.
>>
> great, can you provide links or other information on resetting battery
> packs
> in cases where some information is known.
> Thanks, mike
>
>
>
Anonymous
a b D Laptop
August 30, 2004 2:50:34 AM

Archived from groups: comp.sys.laptops (More info?)

On Sat, 28 Aug 2004 18:52:17 -0700, mike <spamme0@juno.com> wrote:

>Barry Watzman wrote:
>> There are two problems with this:
>>
>> 1. Unless the new cells EXACTLY match the old cells, there is a very
>> real fire/explosion hazard. People have been killed and/or lost limbs
>> because of improper lithium batteries.
>>
>> 2. Almost all laptop LiIon batteries have internal microprocessors that
>> control charging. These have a "memory" (literally", and once they have
>> determined that the battery is bad, they won't let you charge it even if
>> you do replace the cells with good ones. In a very few cases, there is
>> a program to reset these. In a very few other cases, very complex
>> "hacks" have been devised to accomplish the same thing. But in almost
>> all cases, there's nothing that the end-user can do to reset the battery
>> controller.
>>
>great, can you provide links or other information on resetting battery packs
>in cases where some information is known.
>Thanks, mike

http://sweb.cz/Frantisek.Rysanek/battery.html
http://gimel.esc.cam.ac.uk/james/resources/tp240bat/
!