12v adaptor for onboard laptop?

FullCircle

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Anyone bought the cheap adapters from ebay to power laptop on board?
Or is it better to buy something a little more robust?
What wattage do you think I should be looking for?
Is it better to put in a small inverter instead?
Any other interference issues, like engine start voltage dropping?

My lappie is an Advent 7109, with a 240v supply adapter of 19v

Thanks
 
5W - think you mean 120w for modern laptops.

Better to get one capable of supplying at this amount as it wont run as hot as those that can only just cope. I have the 120w and it worked fine at 1 voltage setting below the specced one for the laptop (reduces the charge to the battery) and the last time I used it was cross channel all the time. - not even warm really. The previous one I had was an ebay special that got so hot it burnt out.
 
I got a cheapy from e-bay, about £14 I think, inverters are Soooo excessive as you are double converting! Your laptop (or its power supply) will quote a voltage & power requirement. Simply make sure what you get will handle that power level. Lots are described as car-supplies and most of them will do the job, just watch out for units with inadequate power output.
 
The 3.5A Maplin model is on special offer - £10. I've used it satisfactorily for several years. A tip I was offered to avoid overloading the converter was to either charge the battery or run the laptop - which suggests you shouldn't run the laptop with a flat internal battery - but I have found it copes fine with a 5 year old HP something or other whether the computer battery is flat or not.

Derek
 
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Chech the sine wave as pure is what your units are made to work and modified sine wave will get things running hot .

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He's talking dc - dc .... not inverter !
 
Best is to charge up battery at home ... then take it out. Pack it away as back-up .... plug DC - DC converter in so that it is only running Notebook ... If you rtun with battery in - each time you access CD or other power increasing item ... HHD caddies etc. - the battery will provide initial power and slowly be drained and be topped up by converter. Some of the lower rated converters eventually faile to keep up with battery drain and you end up- with no PC either - till you can get it back on cahrge - OR take battery out !

Don't believe me ? Happens on mine and with careful checking identified exactly above as the reason ....

Of course get hold of a cheapo notebook from ebay etc. - isolate battery and run direct from 12v. Works.
 
I got a cheapy from ebay - comes with lots of different adapters (be careful as they are pole sensitive but can be connected either way round!). Works well on our HP/Compaq (fully charges the battery when the machine is turned on in about 2.5 hours), and on the IBM Thinkpads I've had from work (T23 / T41 / X60).
Doesn't seem to kill the batteries either.

The 'transformer' part seems to get quite warm - but then it is going from 12v DC to a 18 or 20v laptop.

I have mine running via a cigar socket (the cigar socket is fused on the DC panel, and the plug itself has a fuse in it - so hopefully we won't come to grief and damage anything!)

Jonny
 
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