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I recently bought a minivan that has 110V power outlets. I'd like to use my laptop in the van sometimes (not as the driver, of course), but my laptop has a three prong grounded plug, and the outlet is two prong.

What problems might I experience if I use a cheater plug (three prong to two prong adapter)? Why does a laptop need earth ground?

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up vote 3 down vote accepted

You wouldn't experience any problems except in the rare case that your laptop would try to draw too much power from the adapter, causing an overload.

The ground plug is purely for safety and has no effect on the proper operation of an electrical appliance. It accomplishes two things. First, it assures that the plug is inserted with the proper orientation so that the hot wire of the socket is connected in a predictable way to the appliance. Second, the safety ground wire is typically used in appliances that have a conductive case and the case is connected to the safety ground. If a short circuit were to occur inside the appliance, any current will be passed through ground, rather than through the body of someone who touches the conductive case.

The laptop will work just fine if the ground plug is removed or if the hot wire and neutral wire are reversed.

To answer the title of you're question, you may not want to remove the grounding pin because "If the customer alters the product in any way, then all warantees are void. It is, by definition, the customer's fault, whether there are technical reasons or not."

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Assuming that this three wire cord plugs into an external power brick with no exposed metal pieces, you shouldn't have any problems. – Fiasco Labs Nov 25 '11 at 17:27

Your laptop might have a "tingly" sensation coming from a tiny current that runs trough the metallic parts of its case. This is normally solved by plugging it in "backwards".

If your heart is sane and your fingers are dry, this will not be more than a minor annoyance. There are entire countries that do not have grounding...

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Is Thailand one of those countries? – Aki Nov 25 '11 at 15:12
Yes, it is. But there is an abysmal difference between water running through an ungrounded 220 V electric coil and not grounding a 12 V - 24 V laptop. I live in Paraguay. My shower is grounded. The rest of the house is not... – Dennis Nov 25 '11 at 15:25
My old laptop does that, and I live in a country with three-pin plugs and grounding .... – Alan B Nov 25 '11 at 17:04
@Dennis and for a good reason too. I have a friend that lived in Peru for a while. His story about the near death experience by shower and his wife trying to figure out how to pull his spasming body out of the shower stall was not something I'd like to experience. – Fiasco Labs Nov 25 '11 at 17:24

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