I think my laptop is hotter when I plug it into the wall than the surge protector. Does that make sense? [closed]

Question

I have a naive question. In the last few days, I notice my laptop gets hot, even if I'm not doing much ... just leaving it on the table while I read something, or I might be browsing the internet. It was plugged into a extension cord that was plugged straight to the wall.

I know too much current causes the circuit to heat up, so eventually I plugged it instead to a extension cord with a surge protector -- one of these -- http://www.homedepot.com/p/Defiant-6-Outlet-Surge-8-ft-Cord-45-Degree-Angle-Flat-Plug-White-YLPT-43/203353687#.UeLJ41pDvZg (which also has a few more things connected to it). My laptop seems to be not heating up as much.

Does my theory about why my laptop is no longer heating up make sense?

Answer 1

Not really - it all depends on the state your battery was in at the time. If the battery had been previously discharged to some degree then plugged in, it is likely that the laptop will exhibit a different temperature to when the battery is fully charged and then plugged-in.

Also you said: -

I know too much current causes the circuit to heat up

This would be true if the supply voltage from the lap-top's power-pack decided to raise its output voltage a tad - more current may be drawn by some loads and this could raise temperatures but it's likely that even if the power-pack increased its output voltage, energy-efficient switch-mode circuits in the lap-top would reduce their current accordingly in order to take only the exact power they needed.

Answer 2

I might be wrong without a real inspection with equipment, but my first feeling is that any surge protector changes nothing in the voltage/ current supplied. It only stops surges (voltage peaks) produced by power machinery start/ stop or electric storms, which I suppose you don't have every ten seconds at home.

So I'd say your feeling is more psychological than other thing. A cheap way to have a real measurement is to get any software reading the CPU temperature then recording it with and without that thing.

The temperature in a laptop is the result of many things, not only heat generated. If the laptop is placed over a surface like a bed, sofa, etc. the air inlets (usually beneath the laptop) will get blocked and the inside get hotter.

That's why they sell those "laptop coolers" made of aluminium and are basically stands not blocking the air inlets.

Another reason for a laptop running hotter is the air outlet (usually at the side) getting clogged with dust.

Laptop temperatures don't depend only on user or CPU activity. Other peripherals like RAM or HDD also dissipate a fair amount of power which sums up to the heat to be dissipated away. So maybe you are not doing nothing but the anti-virus decides to do the daily scan or your system decides to defragment your disk...