Huh, the manual for the laptop actually says to plug the wall plug first.
Edit: Sorry for bringing this thread back, but I just wanted to say this.
The manufacturer that contracted a supplier to make that charger might have evidence that the output of the charger is not clean (has power spikes) when the charger is first plugged in. Can the laptop's charging circuits handle those power spikes? Maybe the manufacturer opted for the safest set of instructions.
The only issue with leaving the charger plugged in to the outlet all the time is that, even when not charging, it will draw a small amount of current. An individual charger doesn't matter much but when you think of all the millions of chargers in the world then their combined current draw becomes significant. It's just a matter of not wasting energy.
I agree. Laptop chargers, printer wall warts, phone chargers - it all adds up. But it is not easy to get to the wall plug at my desk in my office. We could buy a switch for every charger company wide. How much energy does it take to manufacture 100k switches? When those switches fail - will they end up
here?
Wouldn't be the first time there was a typo in a manual
It makes no practical sense to plug something in a wall socket then connect it to the device
Common sense has to begin some where
It also makes no sense to disconnect a device but leave the cord connected to the outlet :/
If you don't see the real possibility of lightening hitting a power line or power outages and firing your machine that's your choice leave it plugged in all the time.
If you go by this definition of common sense:
Common sense is a basic ability to perceive, understand, and judge things, which is shared by ("common to") nearly all people, and can be reasonably expected of nearly all people without any need for debate.
https://en.wikipedia.org/wiki/Common_sense
This point seems to need some debate - or at least a forum thread
>
It makes no practical sense to plug something in a wall socket then connect it to the device
Are you sure about that? See my comment above about power spikes on the output side.
I would need to move a rather large cabinet to unplug the charger that powers this laptop's docking station at work. In most cases, workers can just crawl under their desk to get to the plug strips that are mounted to the bottom side of the desktop nearest the wall. As I mentioned above, we could add a switch to each charger, but where would we put that switch? We are not allowed to have plug strips on top of the desk. We are not allowed to use extension cords (so a cord with an inline switch is out). Those two rules to be pretty common at large companies. I base that on annual safety classes that I have to suffer thru. These classes are produced by another company and I assume other companies use the class material too.
Yep just plugging in a hot charger into a device could cause the charger to be harmed = grounded against any metal object improperly.
I do not understand what you are saying here. In my case, the outer metal shaft is grounded. It would be hard to have the center pin touch anything by accident. (
image) Even if the outer metal shaft were the positive side of DC, grounding it should not hurt anything. Earth ground and DC ground are probably not the same if the outer metal shaft is positive DC.
Also, the charger should withstand a complete short between the center pin and that outer metal shaft. Output short circuit protection is pretty standard - maybe even a requirement in the US.
The Duracell Universal AC Laptop Adapter has over-current and short circuit protection for reliable power every time, and is backed by a three year warranty.
Source
In my case, the outer metal shaft is connected to earth ground. My charger's power cord has 3 prongs. If you plug the charger into the outlet*, then plug the charger's output into the laptop - any static charge on the laptop is grounded before the center DC positive pin makes contact with the laptop's charging circuits.
*you will hear quite a pop/arc if the charger has been unplugged for a while. I wonder how clean the out put is during that event. I also wonder if the power in that initial surge is greater than the power consumed by leaving it plugged in for 12 hours while the laptop is not connected. If you unplug the charger, you lose some amount of power. Does that make sense? I'm not sure that I'm wording this well.
So would it harm the charger or the laptop? The end that goes in the outlet doesn't have a ground pin, so how would ground work?
~~~
Your charger's output is probably does not ground your laptop in any way. It is not a big deal. Lots of laptop chargers only have two prongs going into the wall outlet. As far has what
ThrashZone said about improper grounding in post #21, I'll have to let him explain that. I think that it was a reference to the charger's output connector touching a different grounded item.
~~~
Also, does that mean the charger should be plugged in when the laptop is off? Or does it not matter?
Not to speak for
ThrashZone, but to outline the order of doing things so that we can discuss this and be on the same page:
1) place laptop on desk -
Power off? Sleep mode? Laptop running?
2) plug the output of the charger into the laptop
3) plug the charger into the AC wall outlet
I think that is what
ThrashZone is saying to do.
I would:
1) place laptop on desk - The state of the laptop does not matter.
2) plug the charger into the AC wall outlet
3) plug the output of the charger into the laptop
It is just common sense
