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All the laptop chargers I had until now sparked whever I plugged them in. This is true for my old charger (the bulkier / rounder Dell model) and the new charger (the flat Dell model) with two different Dell laptops, however until recently I didn't give it much thought.

Then, in the last couple of months:

  • I shorted out a conference room and melted the floor a little (the wire caught fire)
  • The second charger (also a Dell original) died, taking the power strip with it

I'm wondering:

  • Is it normal for laptop chargers to spark when plugged in? Specifically new, original Dell chargers
  • Is there a "correct" way to plug / unplug chargers? Do I need to first unplug it from the wall and then from the laptop / do I need to first plug it into the wall and then into the laptop?
  • May the problem be caused by the fact that I leave sometimes the charger plugged into the wall without connecting the laptop for longer periods of time (up to a day)?

PS. I'm talking about Europe, so 220V and this happens in many places (at home, at my parents, at work, in hotels I trave to, etc)

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Are you sure these are 220V European chargers and not 120V American chargers? It is not normal, and is potentially dangerous, for a charger to spark every time you plug it in. – Jim Sep 21 '11 at 16:31
Yes, they are all 220V chargers (actually they are "universal" - it says 100V - 220V on them) – Cd-MaN Sep 21 '11 at 16:46
It really depends on the quality of the wiring that you normally use. Have you checked to see if your chargers are on any recall lists? – Ramhound Sep 21 '11 at 17:11
Where, exactly, so the sparks come from? – horatio Sep 21 '11 at 19:06
@horatio: the plug end (where I plug it into the wall) sparks. Obviously I can't tell exactly the parts between which the spark forms (ground and one of the wires or between the two wires). – Cd-MaN Sep 22 '11 at 20:02
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5 Answers

up vote 6 down vote accepted

A small spark is normal. The type of power supply on laptops is a switched-mode power supply. With this type of device there is often an "inrush current" that appears as a spark when the prongs of the plug first hit the receptacle contacts (spark usually appears in mid/higher end adapters where a capacitor is used to keep interference down, it is the capacitor that initiates the inrush current and causes the spark).

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up vote 4 down vote

Is there a "correct" way to plug / unplug chargers? Do I need to first unplug it from the wall and then from the laptop / do I need to first plug it into the wall and then into the laptop?

Connect everything first, then as the last step connect the charger to the wall. Make sure that you insert everything all the way as fast as you can by applying a lot of pressure, loose contacts are a known cause of sparks. It also sounds like there is something wrong with the Dell chargers you have, look for alternative options. Just make sure the output is similar in terms of Voltage and Ampere...

May the problem be caused by the fact that I leave sometimes the charger plugged into the wall without connecting the laptop for longer periods of time (up to a day)?

No, while this does use some power it doesn't damage the charger under normal conditions.

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I too suspected the charger, but it seems unlikely to have three problematic chargers bought in two different places. – Cd-MaN Sep 21 '11 at 16:54
There is a possibility of an unbalanced power line coming into the building which causes higher than normal line voltage. But generally this would result in burning out light bulbs, etc -- other symptoms that would be noticed. – Daniel R Hicks Sep 21 '11 at 20:23
up vote 4 down vote

Yes, it's relatively "normal" for a charger to spark when plugging in. Not all will do it, but many high-current chargers will. You may also see a similar spark plugging in a desktop computer.

I've never totally figured out the reason for this phenomenon, but I suspect it's related to the high capacitance inside the charger or power supply. This is the opposite of, eg, an electric motor, which is inductive and where you will see the spark on unplugging.

You should be able to plug/unplug the charger in either order, or leave it plugged in while not connected to the laptop.

And adapters that catch fire (or simply melt down, with the possibility of fire or exposed wiring) should be reported to your national safety agency.

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up vote 0 down vote

My original Dell laptop charger did not have a grounding prong and it did not spark. I recently replaced the original with a compatible replacement charger which has the third grounding prong and with this charger I do get a spark each time the plug is about to be plugged into the socket. But I've never had any performance problems using either type of charger.

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up vote -1 down vote

It is not normal and it's very strange to happen on 2 different chargers, 2 laptops and many places! This can show there is a problem with both charger handling/storage (or maybe on both laptops batteries or connectors). The 1st thing I would investigate is moisture (or dirt) at the place you store the chargers or laptops while not using.

Another thing that may be useful to check would be excessive magnetic fields or static where you store the chargers.

Does the chargers spark when connecting to the wall without being connected to the laptop?

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