I have an old IBM thinkpad whose battery charger outputs 16vdc at 2.2amp. I cut the dc cord and installed some crimp-on eyelets so that it could attach to a small two terminal strip for which I made a cigarette lighter cord. I was able to run that computer charging off my wife's Ford minivan for the 6000 mile trip from MS to AK in spring of 2004. The vehicle voltage is damped by the car's battery and runs about 14.2 volts when the engine is running and sags to 13.2v when off. I never had the computer running when starting the engine. The computer battery will also act as a huge capacitor for smoothing out any voltage spikes.
I also ran my FT-817, 45w amp, KPC-3, and Garmin GPS from the car's battery. The Garmin requires 3.2 volts which was easily provided using a voltage-regulator.
Most cigarette lighters circuits have a 15 to 20 amp fuse on them. That ought to work fine for charging/using with your computer.
73, Ed - KL7UW
At 06:34 AM 4/29/2009, Roger Kolakowski wrote:
A quick inquiry about running a laptop directly off of a cigarette outlet in the car...
for example...let's consider the HP/Compaq series of laptops that take 16-19V from their chargers/power supplies...
Can they be run directly from the auto's 13.6v supply...the available amperage always made me nervous...as does the voltage swings when starting and out of the regulator.
Roger WA1KAT ----- Original Message ----- From: [email protected] To: "Greg D." [email protected]; [email protected] Sent: Wednesday, April 29, 2009 8:52 AM Subject: [amsat-bb] Re: A Fully Rechargeable Satellite Station
Hey Greg,
In addition to the internal rechargeable pack, Yaesu provides a battery
tray for a "DIY" battery pack, and I have been assembling rechargeable individual batteries for these trays. In the case of a longterm power outage, it occurs to me that, as you suggest, a larger 12v battery could come into play. The regular power supply I use in the shack includes the provision to connect a gel cell battery for charging and backup, so that's one option. An auto battery certainly is another although, I suspect I'd opt for a deep-cycle marine battery (or batteries) if I was going to buy them for this use.
My intial plan would be to have enough internal-battery power to get
through at least two "cycles" (i.e., at least two battery packs ready to go for each radio). The hope is that accesss to power from a generator or the larger batteries would be available for recharging the batteries and powering the radios.
As for the computer, the 6-cell pack that is available for the Acer is a
lithion ion pack that, when fully charged, provides up to six hours of continuous use. Given the nature of our satellite passes - in chunks of 10-15 minutes - I have been able to make days worth of passes without a recharge. I hope to pick up another 6-cell battery because I believe two of them would provide the power necessary to handle things until power was available for recharging.
Reading yours and some other comments have me thinking about a few more
elements I need to look into ... things I hadn't given much thought to, but elements that would be helpful to know.
Both on and off the reflector, I've received multiple requests to write
this up for the Journal, and that's very gratifying. I'll definitely do that, and thank everyone for their positive feedback.
73 to all,
Tim
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