computer power in the field

[Arthur Alchin (Arthur Alchin)]

I have a sony Vaio laptop (Athlon 1800+ cpu) which i want to use in the field for running my Meade DSI. The 240VAC transformer steps down to 19.5vdc at about 5amps.

I have 12v adaptor kit to run off cig plug in car but also have 2x 18amp/hr jump starters with aux cig lighter type outputs.

I will use one of these to drive my GOTO on meade but the one for the laptop dries up pretty quick.

Has anybody got any ideas how to extend the llife of the power pack. The laptop is very sensitive to voltage drops and starts to behave in a bizaar fashion in the presence of same.

I would consider running laptop off car but am scared of being battery dead and unable to go home from field work.

All replies will be read with great interest, i love receiving advice from anybody

Arthur

[seeker372011 (Narayan)]

Arthur
after trying various options I finally invested in a 100 amphour gel battery and an invertor and run my laptop of this

it also powers the scope, but that is incidental..the problem is laptops are very power hungry

[Harb]

I use and EU20 Honda genset.
It is so quiet you have to stick your finger up the exhaust to see if its running!!
It is a 2kva unit....bit of overkill, I recon the baby of the range the EU10 would be just the trick 800Watts I think.
The EU 20 runs about 14 hours on a tank of unleaded running everything I plug into it.
I usually put it at the end of a 25m extension lead with the exhaust facing away from everyone, and no one can hear it.
It is an invertor genset, so the power is cleaner than the mains, so is ideal for electronics etc....

cheers
John

[Gama]

What you need to do is not use the power supply for the note book.
This is very inefficient, and so you need a 12V to 18V inverter. You can make these or buy them. I made one for my old LX200, and worked fine. Only a few components, and a small veroboard, or buy one from ebay or somewhere.
Make sure it can supply at least 4 amps.
That should keep your laptop going much better than a AC inverter and switchmode laptop supply.

[Arthur Alchin (Arthur Alchin)]

Thankyou, Now i have some info to work on.

I am going to astrocamp this week coming so may not be able to implement something in the meantime but will have to in future.


Will just have to try and keep power supplies charged up this week

Thankyou again

Arthur

[Omaroo (Chris Malikoff)]

Arthur - you could also install an intelligent battery isolator (like the Piranha DB-150S) in your vehicle, and wire though a set of cables to your second battery, wherever that would fit. You'd want to install a deep cycle battery of at least 100 AH capacity to make it worthwhile, but that would run your scope for quite a while, as well as the laptop. Being isolated, you could run the battery down to 50% or so and not be in the slightest worried because it is isolated from your cranking (starting) battery on the other side of the isolator. If you make the battery removable, you could park it near your scope when you are at the field.

If you didn't want to go with an intelligent isolator, simple solenoid jobs exist from places like ARB and 4WD Wharehouse.

We use this approach to run the traveling fridge when we're away.

Cheers
Chris

[mojo (Terry)]

Originally Posted by Harb

I use and EU20 Honda genset.
It is so quiet you have to stick your finger up the exhaust to see if its running!!

I just looked up the specs for it. 52dB at 7m. That's as quiet as your average dishwasher. Not bad for an internal combustion engine!
Nice one. That would be a worthwhile investment, instead of all this charging of batteries stuff.

[AstroJunk (Jonathan)]

Originally Posted by Gama

What you need to do is not use the power supply for the note book.
This is very inefficient, and so you need a 12V to 18V inverter. You can make these or buy them. I made one for my old LX200, and worked fine. Only a few components, and a small veroboard, or buy one from ebay or somewhere.
Make sure it can supply at least 4 amps.
That should keep your laptop going much better than a AC inverter and switchmode laptop supply.

I use this thing: http://www.kerio.com.tw/products_a_70a.html to great effect. Very power efficient, and hardly touches your car battery.

I've seen them in DSE.