Laptop charging from an inverter

[nomad]

Hi, I have a laptop which has a power supply with a three pin connection. On the top of the transformer it states " connect only to grounded outlet",and in the instruction booklet it says "plug the cord into a grounded (earthed) 3 pin outlet. Do not disable the power cord grounding pin, for example by attaching a two pin adapter, The grounding pin is an important safety feature"

I am planning to use an inverter to recharge while I am away in my motorhome, and am wondering whether connecting a cable to the socket earth connection and running it to a metal pin stuck in the ground would suffice to allow me to charge this way.

Or is it possible that the transformer only has the earth connection to ensure that no-one uses a two pin plug and reverses the pos and neg lines.

 

I hope that someone can give me an answer please,

 

Thanks in anticipation

Colin

[Guest peter]

There might be an earth connection on the inverter from where you could run a wire to ground use Copper or Copper coated rod and make sure ground is wet, not a problem this time of year. If not I would use it without earth connected I do for my Tele' and Sat' receiver. If your worried why not plug an RCD into the inverter and plug the computer into this.

[Clive]

There is no point in fitting an external earth spike for the purpose of protecting the laptop when using an inverter, it will make no difference.

Many inverters do have the output socket NEUTRAL connected internally to the battery supply NEGATIVE lead. This is of course on all modern vehicles is connected to the vehicle chassis. However not all inverters have this link.

 

The reason for the warning may have more to do with EMC and providing a path to drain away static electricity that you may cause to build up on the Laptop when using it.

 

It would be prudent to ensure that a connection exists between the inverter mains socket EARTH connection and the battery NEGATIVE lead to the inverter so that an EMC discharge path to the chassis is assured. The EARTH connection is normally connected to the case of the inverter as well.

 

The Laptop power supply is unlikely to be troubled if the LIVE and NEUTRAL connections are transposed.

 

Regarding fitting an external RCD this will only work if the inverter output NEUTRAL is connected to the chassis (one way or another). If the inverter output is fully isolated then there is no point in fitting an RCD as there is no possibility of any earth current flowing anyway. It would never operate.

 

A few moments with a continuity meter will enable you to check this lot out.

 

Hope that helps.

 

 

 

 

[nomad]

Thank you Peter and Clive for your info and suggestions. I think I will have a look on Ebay for a 12 - 19 volt supply at a reasonable price (£60 plus in PC World) or otherwise use the supplied one to charge but keep watching how it behaves on the first few occasions. I do feel more confident about it now.

Once again MANY THANKS for your interest

Colin

[David Dwight]

Nomad,

 

Maplins do a 12v plug in converter for laptops approx £20

I find it works OK

 

David

[nomad]

Thanks David Im checking Ebay just now Maplins were next on my list

Colin

[Mel E]

When my mains unit for my Toshiba laptop failed whilst in Scotland, I called in at PCWorld and gagged at their price, but fortunately they didn't have one in stock. Went to Maplins, and for about £29 got a mains adaptor which will work with any laptop and even has a built-in fan to keep it cool.

 

I'd certainly go for a mains one via an inverter rather than a 12 volt one, unless the latter has a built-in voltage stabiliser (unlikely at the price quoted).

[Brian Kirby]

Have a look at www.trust.com for a 12V laptop power supply.  I think you can also root out stockists.  It copes with variations in input voltages renging somewhere between 16V and about 10V.  Comes with various connectors to suit different computer power inlet sockets and has stabilised, switchable, output voltages covering most laptop power requirements.  I can't now remember where I got mine, but I'm sure it wasn't £60, or anything like!  However it seems to work very well although it clearly won't run a printer as well as the laptop.  All you need is a 12V DIN socket, or similar, capable of delivering sufficient amparage to run, and charge, your laptop.  The rating plate on your existing power pack should tell all you need to know.  This seems arguably a bit more efficient that going from 12V to 220V and then back to 19V, since only one conversion is involved - though I doubt it make that much difference in practice.

[Dave Newell]

Spot on Brian, I got mine from Action replay at about £40 if i remember but Maplins do voltage stabilised 12V PSUs for laptops for less.

 

D.

[livewire]

just bought a 12v in, 19v out 3500mA supply from ebay £12 delivered. Tried it and its fine

[nomad]

Thanks again everyone for your interest, I have decided to connect my earth pin to the neg lead or chassis as Clive suggested but try to find a 12 volt supply in case of any other problems that arise.

Colin

[tonyishuk]

Take a quick look at Road pro http://www.roadpro.co.uk/ Lots useful stuff mail order is quick,

 

They even phoned to say what I wanted was not in stock but they had what they thought was a better item.

 

They was right too !!

 

Rgds

[messerschmitt owner]

I use a mac and a scanner regularly while away in the motorhome and have never ever had any issues using the power inverter, but then again the mac did come with two pin US plug as well as the UK three pin one and it is designed for use in many countries.

 

I'd say that this also depends on the computer that you are using! Macs, being just plainly better than pcs, have many advantages over them!

 

Campbell

[nomad]

Thanks again everyone for your interest. I think I've cracked it now with an earth connection to the chassis for the inverter output and a 12 to 19 volt power supply from Ebay as backup.

Colin