Power inverter

Associate
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Bonjour

I'm wanting to get a power inverter for my car, so I can run a laptop and various other thingies off it when driving long distance - I am however confused by the wattage issue.

Both the 150 and 300watt varients available claim to be able to run laptops, small fridges and so on and so forth - but does anyone know if there is any advantage to be gained by getting a higher wattage etc?

Cheers
 
Soldato
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Most of the "wattage" ratings are the peak wattage they can provide - the continuous wattage is usually half the advertised power.

Check your laptop adapter, and see what power it uses - then go for an inverter that supplies at least that continuously (ie advertised at at least 2x that power)

The price differences between 300/600/1000 watt ones isn't usually that much - and they'll only supply what's required, but it's always best to have more power available (plus with the higher rated ones you can run multiple things at once!)
 
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Guv said:
Remember anything over 150W and you'll need to run it straight from the battery as it will blow the fuse using the cig lighter

Pah! Crappy little cars! - you cab go beyond 300W in my truck! :cool:

The more power the better, I use a 400w inverter, it runs a lappy, microwave, tv etc with no problems.

It gets damn hot though, ensure its well ventilated, plus, has a kill switch so its not on 24/7 as this'll flatten an HGV's batterys never mind a cars. ;)
 
Caporegime
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BigglesPiP said:
Why convert 12VDC to 240VAC, just so your laptop PSU can convert it back to 12VDC (or thereabouts).

You can get car adaptors for most laptops.

My Dell runs @ 9V - I'd hate to put the 16v my car generates through it never mind the 28v the truck produces.

Thats why in my book. :)
 
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If you were wanting an invterter just for a laptop, you'll be better just buying a universal laptop car adapter for £20, same goes for phone charger
 
Soldato
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R124/LA420 said:
My Dell runs @ 9V - I'd hate to put the 16v my car generates through it never mind the 28v the truck produces.

Thats why in my book. :)

The car kits are usually zener diode based and capable of anything between 12V and 24V input, and more, but they won't guarantee that.
 
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R124/LA420 said:
Pah! Crappy little cars! - you cab go beyond 300W in my truck! :cool:

The more power the better, I use a 400w inverter, it runs a lappy, microwave, tv etc with no problems.

It gets damn hot though, ensure its well ventilated, plus, has a kill switch so its not on 24/7 as this'll flatten an HGV's batterys never mind a cars. ;)

How do you run a microwave off a 400w inverter? Most Microwaves generate at least 800w, plus inefficiencies that must equate to well over 1000w power consumption.
 
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Im pretty sure he can run a microwave because the wattages on microwaves refer to their cooking power (microwave power) rather than their power consumption, although i'd say it would be close to the limit on a 400w!
 
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I use a 150w, 300w peak inverter a lot in my Caravelle, when I am abroad for 3 months at a time, never had a problem with it running my Inspiron 640,and keeping it fully charged, good cheep bit of kit :)
 
Soldato
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My experience of an in car invertor is buying one, plugging my laptop into it, killing the laptops tranformer, giving Samsung £50 for a new one, and relegating the invertor to the depths of a cupboard.
 
Soldato
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A microwave oven only converts part of its electrical input into microwave energy. A typical consumer microwave oven uses 1,100 W AC and produces 700 W of microwave power, an efficiency of 64%. The other 400 W are dissipated as heat, mostly in the magnetron tube
 
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cyborg said:
Im pretty sure he can run a microwave because the wattages on microwaves refer to their cooking power (microwave power) rather than their power consumption,

?

A 150w inverter will easily run a laptop power supply with most maxing out at 80watts. The only advantage for higher rated inverters is the ability to run higher-wattage items from them.

As already mentioned an inverter rated higher than 150w will usually need to be run from the battery terminals as most vehicle cigarette lighter sockets are fused at 10A which equates to 14*10 = 140W (or thereabouts depending on vehicle voltage and fuse current tolerance) maximum allowed with the vehicle engine running.
 
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R124/LA420 said:
My Dell runs @ 9V - I'd hate to put the 16v my car generates through it never mind the 28v the truck produces.

Thats why in my book. :)

The power supplies you can buy for powering your laptop in a car. are very simmilar internaly to the normal mains chargers, i.e. it's a switched mode regulator, but they are designed for 12/24v DC operation rather than 110/240vAC
 
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Dogbreath said:
The power supplies you can buy for powering your laptop in a car. are very simmilar internaly to the normal mains chargers, i.e. it's a switched mode regulator, but they are designed for 12/24v DC operation rather than 110/240vAC

Yep, stop ineffeciencies in the chain and don't have transformers you don't need.

Burnsy
 
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