making my own laptop battery

[Ryan Kremser]

Hello, I have a laptop which has a 4400mah battery which isn't quite enough
for me to use for more than 2 hours. A problem when it comes to some of my
longer flights. I was hoping to make one of the underlaptop battery packs
that i could take with me for longer flights. Battery ac charger for the
computer is rated at 18.5 volts at 4.9 amps. How feasable would it be do
pull this off? What would be the best method for doing it? I've thought
about just using 15 AA cells in series with maybe two banks in parallel so
30 cells but that seems excessive and i'm sure there is a better way, any
suggestions are welcome

 

[Al]

In article <18ae3d0f42bed00203e03b46c64a38d8@news.teranews.com>,
"Ryan Kremser" <news@rkremser.endjunk.com> wrote:

Hello, I have a laptop which has a 4400mah battery which isn't quite enough
for me to use for more than 2 hours. A problem when it comes to some of my
longer flights. I was hoping to make one of the underlaptop battery packs
that i could take with me for longer flights. Battery ac charger for the
computer is rated at 18.5 volts at 4.9 amps. How feasable would it be do
pull this off? What would be the best method for doing it? I've thought
about just using 15 AA cells in series with maybe two banks in parallel so
30 cells but that seems excessive and i'm sure there is a better way, any
suggestions are welcome

Will they let you take a "home-made" battery pack on a plane?

My old laptop used 12VDC in. The on board battery was 7.2V. I just used
a 12 V gel battery like the ones in the UPSs, put a plug on it, and
plugged it into the laptop. You might get away with a 12V and a 6V gel
battry in series. Heavy though, esp with 10AH ratings.

Al

--
There's never enough time to do it right the first time.......

 

[Laurence Payne]

On Wed, 29 Oct 2003 19:37:35 GMT, "Ryan Kremser"
<news@rkremser.endjunk.com> wrote:

Hello, I have a laptop which has a 4400mah battery which isn't quite enough
for me to use for more than 2 hours. A problem when it comes to some of my
longer flights. I was hoping to make one of the underlaptop battery packs
that i could take with me for longer flights. Battery ac charger for the
computer is rated at 18.5 volts at 4.9 amps. How feasable would it be do
pull this off? What would be the best method for doing it? I've thought
about just using 15 AA cells in series with maybe two banks in parallel so
30 cells but that seems excessive and i'm sure there is a better way, any
suggestions are welcome

Before expending too much energy on this project, consider what
airport security's attitude might be to a heavy, non-standard object
strapped to the base of your computer?

 

[Impmon]

On Wed, 29 Oct 2003 19:37:35 GMT, "Ryan Kremser"
<news@rkremser.endjunk.com> typed:

Hello, I have a laptop which has a 4400mah battery which isn't quite enough
for me to use for more than 2 hours. A problem when it comes to some of my
longer flights. I was hoping to make one of the underlaptop battery packs
that i could take with me for longer flights. Battery ac charger for the
computer is rated at 18.5 volts at 4.9 amps. How feasable would it be do
pull this off? What would be the best method for doing it? I've thought
about just using 15 AA cells in series with maybe two banks in parallel so
30 cells but that seems excessive and i'm sure there is a better way, any
suggestions are welcome

I've done something similiar back a few years with Poweerbook Duo. I
had a few dead battery packs, which I took apart and dumped the dead
cells (in recycling) and added 10 D cells rated at 5000 mA in an
external pak cannected to the terminal posts of the old battery pack.

With a new Type 3 battery for Duo, I was averaging about 3 hours, with
my battery pack, I was hitting nearly 20 hours mark. To recharge, I
take out the D cells and put in a standard charger. I know it's extra
steps but my Duo was designed to charge NiMH and the batteries were NiCd
and both charges differently.

I've thought about using auto battery (you're talking hundreds of amps,
not mA) but it's very heavy and acid makes that idea risky.
--
space for rent.
To reply, change digi.mon to tds.net

 

[Lewin A.R.W. Edwards]

Two thoughts:

that i could take with me for longer flights. Battery ac charger for the
computer is rated at 18.5 volts at 4.9 amps. How feasable would it be do

1. It is probably more efficient to go in via the laptop's battery
input, rather than going in the charger input.

2. Home-made apparatus containing batteries and wires is likely to be
viewed with some suspicion at check-in.

 

[mc]

You could always store extra packs in the bottom of the shoes .. and
just have a lead connected to your laptop ..now that would make the
plane staff real jumpy! .. although I do not know if they let you get on
the plane with them

Lewin A.R.W. Edwards wrote:

Two thoughts:


that i could take with me for longer flights. Battery ac charger for the
computer is rated at 18.5 volts at 4.9 amps. How feasable would it be do


1. It is probably more efficient to go in via the laptop's battery
input, rather than going in the charger input.

2. Home-made apparatus containing batteries and wires is likely to be
viewed with some suspicion at check-in.

 

[the Wiz]

"Ryan Kremser" <news@rkremser.endjunk.com> wrote:

Hello, I have a laptop which has a 4400mah battery which isn't quite enough
for me to use for more than 2 hours. A problem when it comes to some of my
longer flights. I was hoping to make one of the underlaptop battery packs
that i could take with me for longer flights. Battery ac charger for the
computer is rated at 18.5 volts at 4.9 amps. How feasable would it be do
pull this off? What would be the best method for doing it? I've thought
about just using 15 AA cells in series with maybe two banks in parallel so
30 cells but that seems excessive and i'm sure there is a better way, any
suggestions are welcome

www.igo.com and look for laptop battery extender. Nicely made, attaches to the
bottom of the laptop, provides lots of extra hours, should ba acceptable to
security.

Or buy the air/auto adapter for the laptop and only fly in aircraft with power
outlets at each seat.

More about me: http://www.jecarter.com/
VB3/VB6/NSBasic Palm/C/PowerBasic source code: http://www.jecarter.com/programs.html
Drivers for Pablo graphics tablet and JamCam cameras: http://home.earthlink.net/~mwbt/
johnecarter at@at mindspring dot.dot com. Fix the obvious to reply by email.

 

[KLR]

On Wed, 29 Oct 2003 19:37:35 GMT, "Ryan Kremser"
<news@rkremser.endjunk.com> wrote:

Hello, I have a laptop which has a 4400mah battery which isn't quite enough
for me to use for more than 2 hours. A problem when it comes to some of my
longer flights. I was hoping to make one of the underlaptop battery packs
that i could take with me for longer flights. Battery ac charger for the
computer is rated at 18.5 volts at 4.9 amps. How feasable would it be do
pull this off? What would be the best method for doing it? I've thought
about just using 15 AA cells in series with maybe two banks in parallel so
30 cells but that seems excessive and i'm sure there is a better way, any
suggestions are welcome

Firstly and most importantly I would be buying the most power
efficient laptop you could find for starters. This is about the only
feasible way to approach this problem overall, but you will possibly
have to settle for a slower processor, smaller screen etc in the
process. I would also fiddle with the power saving settings as much as
possible - and possibly get a screen that can work well with minimal
or no backlighting (on PDA's there is a big difference in quality of
picture and light needed)

As for batteries - You are in real trouble when it comes to the
weight, as your carry on luggage in economy class is about a 5kg
weight limit (even though on our recent trip which involved 6
separate international flights no one at any point did check it for
weight or complained about the 2 of us carrying extra bags of crap on
board with us from the airport shops) so this doesn't allow for much
of a battery weight.

Also you mustn't forget to account for the weight of the charger you
will need for this setup too. It will also need to be fast,
lightweight and suitable for international voltages too, so switchmode
would really be the ideal choice. In some airports you are only there
for a short time between flights - so you want a type of battery and
charger that will refill FAST when you do find a power point !

Connecting directly to the actual battery terminals of the laptop
would be preferable to connecting to the charger input - as there may
be significant losses and inefficiencies involved with powering it
this way.

Another problem as mentioned elsewhere is taking a home made
electrical device such as this through airport security. I recently
made up a small zippy box with an inbuilt 2ah SLA battery for my
recent trip - and the various connectors / leads etc for my camera and
portable hard drive used with the camera. I also included a connector
so it could be recharged via mobile phone charger. This setup worked
really well for me. Only once did airport security (while leaving
moscow airport) demand to see this device and know what it was - and
they accepted my description without too much trouble.

If I was carrying something much larger and heavier though - I would
suggest mounting it in a case - with one side being clear (such as
perspex) so the internals can be easily identified in this situation.
Using those plastic electrical boxes (intended for wall mounting) from
haymans etc that have the clear moulded front and a large screw at
each corner would probably be the go. They would probably be much
tougher and impact resistant as a bonus.

Something that large and of metal such as a 10-20AH battery (on the
x-ray machine) would most certainly be pulled out and inspected - and
in the process the issue of cabin baggage weight limit might be
brought up too - so be careful)

Having a fuse and an isolation switch would also be a must - as the
last thing you want is for a short circuit to happen and have the
thing start to melt down under your seat and no way of stopping it.
Recess the fuseholder and switch a bit so as they dont hit anything
and break off as they would if protruding from the outside of the case

There is a lot more to this project than first meets the eye.

 

[KoRRupT]

"Ryan Kremser" <news@rkremser.endjunk.com> wrote in message
news:18ae3d0f42bed00203e03b46c64a38d8@news.teranews.com...

Hello, I have a laptop which has a 4400mah battery which isn't quite
enough
for me to use for more than 2 hours. A problem when it comes to some of
my
longer flights. I was hoping to make one of the underlaptop battery packs
that i could take with me for longer flights. Battery ac charger for the
computer is rated at 18.5 volts at 4.9 amps. How feasable would it be do
pull this off? What would be the best method for doing it? I've thought
about just using 15 AA cells in series with maybe two banks in parallel so
30 cells but that seems excessive and i'm sure there is a better way, any
suggestions are welcome

1. get a second laptop battery. don't get an original. after market ones are
just as good, sometimes half the price. just picked up one for my Toshiba
original RRP was $245, aftermarket $110 - exactly the same and with a little
bit more capacity.

2. don't use AA, use D's. more capacity. see if you can find Li-Ion. Much
much lighter than Ni-Cd and NMH.

3. go to a battery specialist (battery world?) and see if they can re-pack
larger capacity ones for you.

 

[Watson A.Name - "Watt Sun]

In article <18ae3d0f42bed00203e03b46c64a38d8@news.teranews.com>,
news@rkremser.endjunk.com mentioned...

Hello, I have a laptop which has a 4400mah battery which isn't quite enough
for me to use for more than 2 hours. A problem when it comes to some of my
longer flights. I was hoping to make one of the underlaptop battery packs
that i could take with me for longer flights. Battery ac charger for the
computer is rated at 18.5 volts at 4.9 amps. How feasable would it be do
pull this off? What would be the best method for doing it? I've thought
about just using 15 AA cells in series with maybe two banks in parallel so
30 cells but that seems excessive and i'm sure there is a better way, any
suggestions are welcome

Speaking from my experiences with Dell the LiIon batteries are smart,
ans have circuit boards inside to control the charge and discharge.
If you don't have these, things might get a little out of hand. But
adding them is more than a little bit of a challenge. I suggest you
carry a spare factory-made battery instead.


--
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[Ryan Kremser]

Reading all of the posts, it does make a lot of sense just to go out and buy
another battery for the laptop. While the price is still a bit higher than
i had hoped the issues even with the airport security will come into play
which i had not even considered before. thanks again for the input


"Ryan Kremser" <news@rkremser.endjunk.com> wrote in message
news:18ae3d0f42bed00203e03b46c64a38d8@news.teranews.com...

Hello, I have a laptop which has a 4400mah battery which isn't quite
enough
for me to use for more than 2 hours. A problem when it comes to some of
my
longer flights. I was hoping to make one of the underlaptop battery packs
that i could take with me for longer flights. Battery ac charger for the
computer is rated at 18.5 volts at 4.9 amps. How feasable would it be do
pull this off? What would be the best method for doing it? I've thought
about just using 15 AA cells in series with maybe two banks in parallel so
30 cells but that seems excessive and i'm sure there is a better way, any
suggestions are welcome

 

[Impmon]

On Thu, 30 Oct 2003 13:32:45 +1030, "KoRRupT" <me@nowhere> typed:

2. don't use AA, use D's. more capacity. see if you can find Li-Ion. Much
much lighter than Ni-Cd and NMH.

Watch out, some C's and D's are just AA's or even AAA's in larger case.
If the mAh rating for D is very close to or the same as AA, it's
probably a cheap stuff. For NiMH, I often find decent D's in 5000 to
6000 mAh.
--
space for rent.
To reply, change digi.mon to tds.net

 

[Russ]

"Baphomet" <fandaDEATH2SPAMMERS@catskill.net> wrote in message
news:vq20tqedo15af0@corp.supernews.com...

"Laurence Payne" <l@laurenceDELETEpayne.freeserve.co.uk> wrote in message
news:12a0qvo2034nhh9ejf5mmp8gv9lso0o46g@4ax.com...
On Wed, 29 Oct 2003 19:37:35 GMT, "Ryan Kremser"
news@rkremser.endjunk.com> wrote:

Hello, I have a laptop which has a 4400mah battery which isn't quite
enough
for me to use for more than 2 hours. A problem when it comes to some
of
my
longer flights. I was hoping to make one of the underlaptop battery
packs
that i could take with me for longer flights. Battery ac charger for
the
computer is rated at 18.5 volts at 4.9 amps. How feasable would it be
do
pull this off? What would be the best method for doing it? I've
thought
about just using 15 AA cells in series with maybe two banks in parallel
so
30 cells but that seems excessive and i'm sure there is a better way,
any
suggestions are welcome


Before expending too much energy on this project, consider what
airport security's attitude might be to a heavy, non-standard object
strapped to the base of your computer?

Point well taken ;-)

About 5 years ago I did a round the world trip - Europe and the US - I took
my DAT player with me for music and rigged up a fairly chunky 6v gel cell
for power. Even in those days I though the cell and wires would look pretty
suspicious going through the x-ray, but over 20 flights through different
airports it never caught anyone's attention.

I'd never try the same thing these days!

Russ.

 

[KLR]

On Fri, 31 Oct 2003 01:12:23 +1100, "Russ" <russ_spmtrp@hotmail.com>
wrote:

"Baphomet" <fandaDEATH2SPAMMERS@catskill.net> wrote in message
news:vq20tqedo15af0@corp.supernews.com...

"Laurence Payne" <l@laurenceDELETEpayne.freeserve.co.uk> wrote in message
news:12a0qvo2034nhh9ejf5mmp8gv9lso0o46g@4ax.com...
On Wed, 29 Oct 2003 19:37:35 GMT, "Ryan Kremser"
news@rkremser.endjunk.com> wrote:

Hello, I have a laptop which has a 4400mah battery which isn't quite
enough
for me to use for more than 2 hours. A problem when it comes to some
of
my
longer flights. I was hoping to make one of the underlaptop battery
packs
that i could take with me for longer flights. Battery ac charger for
the
computer is rated at 18.5 volts at 4.9 amps. How feasable would it be
do
pull this off? What would be the best method for doing it? I've
thought
about just using 15 AA cells in series with maybe two banks in parallel
so
30 cells but that seems excessive and i'm sure there is a better way,
any
suggestions are welcome


Before expending too much energy on this project, consider what
airport security's attitude might be to a heavy, non-standard object
strapped to the base of your computer?

Point well taken ;-)

About 5 years ago I did a round the world trip - Europe and the US - I took
my DAT player with me for music and rigged up a fairly chunky 6v gel cell
for power. Even in those days I though the cell and wires would look pretty
suspicious going through the x-ray, but over 20 flights through different
airports it never caught anyone's attention.

I'd never try the same thing these days!

Russ.

I don't think you would have too much trouble with it, and I wouldnt
worry too much about taking such an item.

A month ago - out of 6 customs inspections round the world - only one
was I questioned about it they accepted my explaination without much
hassle. I do think in hindsight it might be a good idea to put a
clear perspex window in the side and arrange the internals so anyone
can clearly see that it contains a battery etc though. Putting the
side of the battery with its part number - specs etc facing this
window would also be an idea.

The thing I would worry more about - is if it was a really large
battery is that if it was inspected etc - they might start complaining
that it exceeds the cabin baggage weight limit, which they normally
dont seem to care much about enforcing

 

[Baphomet]

"Laurence Payne" <l@laurenceDELETEpayne.freeserve.co.uk> wrote in message
news:12a0qvo2034nhh9ejf5mmp8gv9lso0o46g@4ax.com...

On Wed, 29 Oct 2003 19:37:35 GMT, "Ryan Kremser"
news@rkremser.endjunk.com> wrote:

Hello, I have a laptop which has a 4400mah battery which isn't quite
enough
for me to use for more than 2 hours. A problem when it comes to some of
my
longer flights. I was hoping to make one of the underlaptop battery
packs
that i could take with me for longer flights. Battery ac charger for the
computer is rated at 18.5 volts at 4.9 amps. How feasable would it be do
pull this off? What would be the best method for doing it? I've thought
about just using 15 AA cells in series with maybe two banks in parallel
so
30 cells but that seems excessive and i'm sure there is a better way, any
suggestions are welcome


Before expending too much energy on this project, consider what
airport security's attitude might be to a heavy, non-standard object
strapped to the base of your computer?

Point well taken ;-)