240v Inverter For Laptop

[V8RX7]

I'm running an old laptop with a serial port to tune my MX5.

I was using an old 150w inverter but it kept beeping "insufficient power" then the laptop battery died.

The laptop's own battery works for 30mins and it seems uses max 150w so I presume it meant there was insufficient power from the car ?

But as the car can happily run everything it uses I can't see that's correct.

Is it just a case of buying a new inverter in which case should a 150W be sufficient or do I need to overspec it ?

[TooMany2cvs]

V8RX7 said:

I'm running an old laptop with a serial port to tune my MX5.

I was using an old 150w inverter but it kept beeping "insufficient power" then the laptop battery died.

The laptop's own battery works for 30mins and it seems uses max 150w so I presume it meant there was insufficient power from the car ?

But as the car can happily run everything it uses I can't see that's correct.

Is it just a case of buying a new inverter in which case should a 150W be sufficient or do I need to overspec it ?

You need to look in to the input power for the laptop's power brick, and the output power of the inverter. That 150w will probably be the input power of the inverter - even that's borderline for a ciggy socket, though - 10A @ 14v = 140w.

You'd be best, though, getting a 12v power brick. Then you're not adding inefficiencies together by going 12v -> 230v -> 12v or whatever.

[TurboHatchback]

You'll need a true sine wave inverter for a laptop. The cheap inverters are invariably square wave inverters which is fine for resistive loads but useless for inductive loads such as the transformer in a laptop power supply. I bought one from Amazon for about £70 for my trip to Iceland and it worked very nicely, can't remember which model it was though.

[V8RX7]

Hmmm I have a large boost pack which is obviously 12v

I see there are things like this:

http://www.ebay.co.uk/itm/Car-CHARGER-for-Dell-Lat...

But I thought DC DC couldn't step up

[Craikeybaby]

We use the Dell 12v power bricks for running laptops in cars.

We also use DC:DC convertors in some of the ECUs we develop, so it is possible.

[Tinkshusband]

TurboHatchback said:

You'll need a true sine wave inverter for a laptop. The cheap inverters are invariably square wave inverters which is fine for resistive loads but useless for inductive loads such as the transformer in a laptop power supply. I bought one from Amazon for about £70 for my trip to Iceland and it worked very nicely, can't remember which model it was though.

my cheapy ring 150w works fine with my macbook air. but thats only a 45w draw so maybe that makes some difference.