[TenTec] RE: Lap Top Battery..Charging .And My Argo V portable or mobile.

[Hsu, Aaron]

Larry,

The "excess" voltage and current requirements for the laptop power adapter
are generally to help facilitate charging the battery.

Most laptops I've worked with generally use an AC adapter that's +4 to +5
volts above the battery voltage.  As you've noticed, the Tecra 8000 battery
is 10.8 volts and most "business class" Toshiba laptops use the 15v/3A
adapter.  The laptops themselves have a DC/DC converter that will step-down
the voltage to the +5, +3.3, +1.6, etc that the system components actually
need.  There's also a step-up for the LCD backlight.

The current requirements of the adapter must be enough to both meet the
demands of a "powered on" system *AND* charging the battery.  I've run into
situations where clients used an older 15v/2A adapter on their new laptop
and wondered why the battery wouldn't charge even though they kept it
"plugged-in" all night.  Well, they also left the laptop powered-up and
there wasn't enought current available to also charge the battery.

I've run both my Toshiba 7220CT and Compaq N400C laptops directly off an
Astron power supply during contests and suffered no ill effects.  As long as
the DC/DC converter has enough overhead, there shouldn't be much problem.
The internal battery may not charge (or might take longer), but it should
keep it's existing charge.  Try this: fully charge your external battery and
the laptop, turn off all power savings in the laptop (including the screen
saver), plug the laptop directly into the external battery, and see if if
runs for more than the normal length of time your laptop battery lasts.  If
it does, then the external battery should keep you going.  Being a laptop,
it will warn you when the batteries are low and should go into hibernation
if it drops to below 2% (if hibernation is enabled).


73,

  - Aaron Hsu, NN6O (ex-KD6DAE)
    {nn6o}@arrl.net
    {athsu}@unistudios.com
    No-QRO Int'l #1,000,006
    . -..- - .-. .-   ".... . .- ...- -.--"
 



-----Original Message-----
From: Larry Greenberg N5BEA [mailto:larrylg1 at excite.com]
Sent: Tuesday, April 20, 2004 9:58 PM
To: tentec at contesting.com
Subject: [TenTec] Lap Top Battery..Charging .And My Argo V portable or
mobile.


 Hoping to not be too far off base.  For travel or  for my simple "12"
(14.1) volt emergency power well now that I have an Argo  I am curious if
any one has experienced long term use of a laptop computer that might make
both situations better. I have not found out much information from the
computer factory.  My laptop computer power section knowledge is very
limited.. My model number is Toshiba Tecra 8000.  The AC adapter produces 15
volts dc @ 3 amps the battery is 10.8 volts.. ..   I guess that I could buy
a cheap inverter if there is somthing that picky in the circuit.  Anyway,
.It is natrual that someone uses his/her  Argo `& laptop portable or
mobile.    

Larry Greenberg N5BEA