laptops charging

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sinbad1

Deleted User
Thinking of ways of powering a laptop, when hookup is not available.

I have read some inverters can cause the laptop transformers to get hot , presumably this is a result of a modified sine wave rather than a pure one.

Just had alook in Mapins at this 70W Laptop Car Adaptor > Maplin The guy in the shop said it should work ok with laptops ;but i've got my doubts? 70w seems small allthough i think they do a 120W version

I like the idea of converting 12v to 19v rather than 12v to 240v to 19v ;but will it work.?
would appreciate your thoughts.

Regards
 
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Papa Smurf

Member
Sep 25, 2007
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Yes, 12v --> 19v does work. Laptops use around 90w so calculate how long you can use it for :)
 
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sinbad1

Deleted User
Yes, 12v --> 19v does work. Laptops use around 90w so calculate how long you can use it for :)

I would have thought it would use more than 90w , so would expect a few hours use (excluding whats left in the lappies battery).

Regards
 
Jun 18, 2008
1,530
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This one is recommended for computers, it's even available from Apple's own store (but at a very inflated price)

Kensington Ultra Portable Power Inverter 150W
[ame=http://www.amazon.co.uk/Kensington-Ultra-Portable-Power-Inverter/dp/B000HEW0KM/ref=sr_1_1?ie=UTF8&s=electronics&qid=1232567485&sr=8-1]Kensington Ultra Portable Power Inverter 150 - DC to AC: Amazon.co.uk: Electronics & Photo[/ame]
 
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sinbad1

Deleted User
This one is recommended for computers, it's even available from Apple's own store (but at a very inflated price)

Kensington Ultra Portable Power Inverter 150W
Kensington Ultra Portable Power Inverter 150 - DC to AC: Amazon.co.uk: Electronics & Photo

Thanks for the link;but the unit is for DC to AC then the laptops power supply would have to convert it back to DC 19v, this can cause problems as inverters are normally modified sine wave , transformers don't like that unless they are pure sine wave and they cost more:Sad:

Regards
 
Apr 27, 2008
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Eastbourne East Sussex
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I have one of the Maplins bargains and it is very good.

70w is low and some laptops will warn that the are going into a power saving mode at a slower processor speed (though if it didn't warn you you probably wouldn't notice). In any case it will still charge, its only if you're charging it and using it at the same time that there may be any problem.
I can recommend these, they do what they say at a low price and draw much less current from the batteries than an inverter.:thumb:
 

Phil

Free Member
Oct 21, 2007
226
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Coachbuilt
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If you look on the bottom of your laptop's mains charger it should tell you the output voltage and current. If you multiply these 2 figures together you will know how many watts you need.

Maplins sell different laptop power supplies which convert the battery 12v to the dc voltage required by different laptops. My Acer for instance requires 19v at 6 amps which is 114 watts. I know Maplins sell 6 amp 120 watt units as I was thinking of getting one for our holidays. More modern laptops require less so as I said check on your charger then you will be able to decide which one you should buy.

Phil.
 
OP
S

sinbad1

Deleted User
If you look on the bottom of your laptop's mains charger it should tell you the output voltage and current. If you multiply these 2 figures together you will know how many watts you need.

Maplins sell different laptop power supplies which convert the battery 12v to the dc voltage required by different laptops. My Acer for instance requires 19v at 6 amps which is 114 watts. I know Maplins sell 6 amp 120 watt units as I was thinking of getting one for our holidays. More modern laptops require less so as I said check on your charger then you will be able to decide which one you should buy.

Phil.
Thanks the transformer actually shows the wattage as 90 so its going to be the 120w unit 120W Laptop Car Adaptor > Maplin

Regards
 
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