rebuild old laptop battery pack-- waste of time or worth it?

I am in the process of using one of my old laptops for a specific task.
Of course, due to age, one of the issues I've come across is battery
life. Under any stress, the battery lasts maybe 20 min. If I do
nothing, it may go on for 45 min. Recently, I came across a few videos
where folks rebuilt their laptop battery packs and I'm wondering if it's
worth it for this old machine. Without too much effort, I managed to
disassemble the Lithium Ion pack and it is made up of 9 cells labelled
as Sony Energytec US17670 which, according to my research, are 3.6 V
cells and, as luck would have it, here is the same pack disassembled:

https://wiki.droids-corp.org/article...nics/Accu.html

Now the big question is: 1) Is it worth it to replace these cells? Some
quick searching is showing them being quite expensive even for "generic"
cells which I understand probably wouldn't last any longer than the time
I'm getting now. The next question would be 2) If worth it, what would
be a suggested source for obtaining the replacements? Finally (3) is
there any way simple way to increase power on time of these current
cells? I have read of people putting them in the freezer, etc, but I
don't think that's for this type of battery.

If all else fails, I'll just continue using the AC adapter.

Thanks.

David on 2017/01/18 wrote:

I am in the process of using one of my old laptops for a specific task.
Of course, due to age, one of the issues I've come across is battery
life. Under any stress, the battery lasts maybe 20 min. If I do
nothing, it may go on for 45 min. Recently, I came across a few videos
where folks rebuilt their laptop battery packs and I'm wondering if it's
worth it for this old machine. Without too much effort, I managed to
disassemble the Lithium Ion pack and it is made up of 9 cells labelled
as Sony Energytec US17670 which, according to my research, are 3.6 V
cells and, as luck would have it, here is the same pack disassembled:

https://wiki.droids-corp.org/article...nics/Accu.html

Now the big question is: 1) Is it worth it to replace these cells? Some
quick searching is showing them being quite expensive even for "generic"
cells which I understand probably wouldn't last any longer than the time
I'm getting now. The next question would be 2) If worth it, what would
be a suggested source for obtaining the replacements? Finally (3) is
there any way simple way to increase power on time of these current
cells? I have read of people putting them in the freezer, etc, but I
don't think that's for this type of battery.

If all else fails, I'll just continue using the AC adapter.

Since you never divulged the actual brand and model of your laptop, no
one here would know what is the current sales price to acquire a brand
new main battery. How could there be a comparison between the cost to
doing a rebuild (buying the batteries, hoping you don't destroy them by
soldering since it is unlikely you have a sonic welding machine) to
buying a new battery.

How are you going to wire together the batteries? They are lithium
which means you cannot use a heated soldering iron. Did you find
lithium batteries that already have a tang attached to them? If so,
will those batteries still fit inside the battery case?

https://xaeus.wordpress.com/2014/04/...mal-damage-en/
"It is not advised by the battery manufacturers to heat them up
regardless the reason. By using heat on Li-Ion cells, you can damage the
plastic separator, pressure protections or even the main internal
lithium layers."

Also, most times the caps on the battery will not take to soldering. It
won't bond even when scratching (scrubbing) the contact acrea and using
rosin to prep the surface. I have seen batteries you can buy with tangs
already pre-attached. Those had the tangs attached when manufacturing
the cap, not by soldering on a constructed battery.

This is not a Windows 7 issue, or any software issue. It is a hardware
issue. The folks visiting the comp.hardware.* newsgroups might provide
a better audience.

On 01/18/2017 10:37 AM, VanguardLH wrote:
David on 2017/01/18 wrote:

I am in the process of using one of my old laptops for a specific task.
Of course, due to age, one of the issues I've come across is battery
life. Under any stress, the battery lasts maybe 20 min. If I do
nothing, it may go on for 45 min. Recently, I came across a few videos
where folks rebuilt their laptop battery packs and I'm wondering if it's
worth it for this old machine. Without too much effort, I managed to
disassemble the Lithium Ion pack and it is made up of 9 cells labelled
as Sony Energytec US17670 which, according to my research, are 3.6 V
cells and, as luck would have it, here is the same pack disassembled:

https://wiki.droids-corp.org/article...nics/Accu.html

Now the big question is: 1) Is it worth it to replace these cells? Some
quick searching is showing them being quite expensive even for "generic"
cells which I understand probably wouldn't last any longer than the time
I'm getting now. The next question would be 2) If worth it, what would
be a suggested source for obtaining the replacements? Finally (3) is
there any way simple way to increase power on time of these current
cells? I have read of people putting them in the freezer, etc, but I
don't think that's for this type of battery.

If all else fails, I'll just continue using the AC adapter.

Since you never divulged the actual brand and model of your laptop, no
one here would know what is the current sales price to acquire a brand
new main battery. How could there be a comparison between the cost to
doing a rebuild (buying the batteries, hoping you don't destroy them by
soldering since it is unlikely you have a sonic welding machine) to
buying a new battery.

How are you going to wire together the batteries? They are lithium
which means you cannot use a heated soldering iron. Did you find
lithium batteries that already have a tang attached to them? If so,
will those batteries still fit inside the battery case?

https://xaeus.wordpress.com/2014/04/...mal-damage-en/
"It is not advised by the battery manufacturers to heat them up
regardless the reason. By using heat on Li-Ion cells, you can damage the
plastic separator, pressure protections or even the main internal
lithium layers."

Also, most times the caps on the battery will not take to soldering. It
won't bond even when scratching (scrubbing) the contact acrea and using
rosin to prep the surface. I have seen batteries you can buy with tangs
already pre-attached. Those had the tangs attached when manufacturing
the cap, not by soldering on a constructed battery.

This is not a Windows 7 issue, or any software issue. It is a hardware
issue. The folks visiting the comp.hardware.* newsgroups might provide
a better audience.

I think maybe I'll just continue using the AC adapter. It does hold
some charge as I said, so if the cord accidentally comes out, at least
it won't go off right away.

Odd that the Youtube vids though make the process look fairly easy, but
most didn't cover battery cost for decent batteries, not the Chinese
made ones.

The laptop in question is a Toshiba Satellite 490.

On Wed, 18 Jan 2017 09:37:43 -0600
VanguardLH wrote:

, no
one here would know what is the current sales price to acquire a brand
new main battery.

So then why write a worthless word wall??

David on 2017/01/18 wrote:

On 01/18/2017 10:37 AM, VanguardLH wrote:
David on 2017/01/18 wrote:

I am in the process of using one of my old laptops for a specific task.
Of course, due to age, one of the issues I've come across is battery
life. Under any stress, the battery lasts maybe 20 min. If I do
nothing, it may go on for 45 min. Recently, I came across a few videos
where folks rebuilt their laptop battery packs and I'm wondering if it's
worth it for this old machine. Without too much effort, I managed to
disassemble the Lithium Ion pack and it is made up of 9 cells labelled
as Sony Energytec US17670 which, according to my research, are 3.6 V
cells and, as luck would have it, here is the same pack disassembled:

https://wiki.droids-corp.org/article...nics/Accu.html

Now the big question is: 1) Is it worth it to replace these cells? Some
quick searching is showing them being quite expensive even for "generic"
cells which I understand probably wouldn't last any longer than the time
I'm getting now. The next question would be 2) If worth it, what would
be a suggested source for obtaining the replacements? Finally (3) is
there any way simple way to increase power on time of these current
cells? I have read of people putting them in the freezer, etc, but I
don't think that's for this type of battery.

If all else fails, I'll just continue using the AC adapter.

Since you never divulged the actual brand and model of your laptop, no
one here would know what is the current sales price to acquire a brand
new main battery. How could there be a comparison between the cost to
doing a rebuild (buying the batteries, hoping you don't destroy them by
soldering since it is unlikely you have a sonic welding machine) to
buying a new battery.

How are you going to wire together the batteries? They are lithium
which means you cannot use a heated soldering iron. Did you find
lithium batteries that already have a tang attached to them? If so,
will those batteries still fit inside the battery case?

https://xaeus.wordpress.com/2014/04/...mal-damage-en/
"It is not advised by the battery manufacturers to heat them up
regardless the reason. By using heat on Li-Ion cells, you can damage the
plastic separator, pressure protections or even the main internal
lithium layers."

Also, most times the caps on the battery will not take to soldering. It
won't bond even when scratching (scrubbing) the contact acrea and using
rosin to prep the surface. I have seen batteries you can buy with tangs
already pre-attached. Those had the tangs attached when manufacturing
the cap, not by soldering on a constructed battery.

This is not a Windows 7 issue, or any software issue. It is a hardware
issue. The folks visiting the comp.hardware.* newsgroups might provide
a better audience.

I think maybe I'll just continue using the AC adapter. It does hold
some charge as I said, so if the cord accidentally comes out, at least
it won't go off right away.

Odd that the Youtube vids though make the process look fairly easy, but
most didn't cover battery cost for decent batteries, not the Chinese
made ones.

The laptop in question is a Toshiba Satellite 490.

Can you buy just the battery cells for under $30? That's the price I
see for a whole new 9-cell battery pack at eBay.

Since it is an old laptop, it probably needs a new CMOS battery, too.
Those can be tought to replace.

David wrote:


I think maybe I'll just continue using the AC adapter. It does hold
some charge as I said, so if the cord accidentally comes out, at least
it won't go off right away.

Odd that the Youtube vids though make the process look fairly easy, but
most didn't cover battery cost for decent batteries, not the Chinese
made ones.

The laptop in question is a Toshiba Satellite 490.



I can still see the 9 cell as well as 6 cell versions
of that pack.

https://www.thelaptoppowersupplyshop...-battery-77960

You would have to compare the specs to the label on your
current product, to see if the rating has improved over
the years.

Volts: 10.8VDC
Amps: 4500mAh
Watts: 49Wh

Battery packs age just sitting on the shelf. In addition,
the initial charge on the pack, could run out, and once
a pack falls below the minimum voltage, the charger is
not supposed to charge it. That's a safety issue too, that
applies when more than one cell is used to build a pack.
For example, my digital camera has a 1 cell battery, and
on those, you can run the battery flat, and the charger
will still charge it (this actually happened so I got
to test it and verify everything with a multimeter).

Whereas, with the larger packs, if they fall below a
minimum voltage (such that one cell can be reverse biased),
then for safety, the charger is not allowed to charge it.

You could carry a UPS into the back yard, and run the
adapter off that, for remote operation. (Or a marine battery
plus an inverter.) But the battery in the UPS would need
to be quite large, to run your setup for a long time. You
don't really want to be discharging and charging the UPS
over and over again, if you can help it. For car batteries,
they should only be discharged to a depth of maybe 20%, whereas
the more expensive marine battery allows a deeper discharge.

They also make "power packs", which is a lithium ion
pack - typical value might be 5V out. Those can be used to
run USB charged mobile devices on a camping trip.
The packs feature low-voltage-cutoff, so the battery
protects itself against complete discharge. But the
odds of a "power pack" putting out exactly the same voltage
as the DC adapter that runs your laptop are slim. Generally
speaking, for best results, a replacement adapter should
be within +/-0.5V of the original spec, to avoid problems.
(Someone in the newsgroup used an adapter that didn't
meet that requirement, on their laptop, and the setup
lasted about a month before failing. The laptop appeared
to be damaged by it. That's why you have to match them.)

(While it has an output labeled "12V-20V", it doesn't say
how the voltage is set. It appears it only has a "high-low"
switch, so is not suitable for precise applications. In the
Q-A section, the customer service says it is 135Wh, or about
2.5 times your 9-cell pack. The third customer review, reports
a device damaged while using the pack.)

https://www.amazon.com/Abyone-SPC50B...15v+power+pack

Fiddling with this stuff, is only for rocket scientists. Running
an AC cord to the back yard is a lot easier.

*******

As for battery packs, the conductor strips are cold-spot-welded
onto the battery terminals. That's how they avoid soldering. It
looks like your pack places three cells in parallel, and puts
three of those groups in series. It could be something like this.

Plus --+----+----+ +----+----+----+ +----+----+----+
| | | | | | | | | | |
+ + + | + + + | + + +
Cell Cell Cell | Cell Cell Cell | Cell Cell Cell
- - - | - - - | - - -
| | | | | | | | | } |
+----+----+----+ +----+----+----+ +----+----+-- Minus

To carry out that pattern, the three cells in parallel must
have the same terminal voltage during the weld operation.
If the cells are unbalanced, large loop currents can flow.
At the factory, perhaps the weld happens while the cell is
discharged ? Dunno. The charging rules at the factory are
different than for the end-user, because at the factory
they have knowledge of whether a reverse-bias could happen
or not in the production line.

If you were doing this, I'd be less concerned. Now, there's
only the weld-quality to worry about.

Plus --+----+----+ +----+----+----+ +----+----+----+
| | | | |
+ | + | +
Cell | Cell | Cell
- | - | -
| | | | |
+----+----+----+ +----+----+----+ +----+----+-- Minus

There have been batteries with tabs pre-welded onto them,
but then you have to worry about making some sort of fitting
for whatever the tab looks like.

I've only re-done a NiCd pack, and that worked out
OK. (I actually started with a commercial pack, with
spot-welded tabs already on it, and recycled the cells
into the device needing repair. I was careful to select
quick-charge cells to match the original type.) I'm
sure by now, the recipient has a dead NiCd pack and
another mess on their hands, as these hacks don't
last forever. I wouldn't dare do a Lithium one...
My homeowner insurance might not cover it :-)

Batteries are a curse.

Paul