Do laptops talk to their power supply?
 

Is a laptop power supply "intelligent" in that it adjusts its own behaviour based on the state of the laptop's charge (whether it's the laptop telling the PSU what to do or the PSU actively detecting its state)?

Or is it just a transformer?

Within a few days of noticing the laptop doesn't stop charging when 100% full, I've seen a little break in the cable rubber with exposed wire that may or may not be related. I'd don't want have it repaired or buy a new one if I thought it would not fix the problem.

Re: Do laptops talk to their power supply?
 

Usually incoming calls only, i.e. it draws the power from the supply but doesn't talk back, the circuitry within the laptop can tell if the battery is charged and cuts down on the amount of charge when required.

Howstuffworks "Laptop Batteries"

http://planetsmilies.net/violent-smiley-1654.gif

Re: Do laptops talk to their power supply?
 

To add to what Less has said, in general a laptop PSU will have a plug on the end of the cable (that plugs into the laptop) that has only 2 connections, usually +19v(ish) & 0v.

Once the batteries are charged they will draw less current from the PSU/charger, all the psu/charger will do is supply less current (it won't force it all down the wires).

(A bit like filing a bucket from out of a bath, once the bucket is full it cannot be filled any more but you can still dip it in the bath :D )

If yours is still working OK despite this little nick in the cable then you need not worry.
(Unless the nick is in the mains lead that supplies the PSU, in which case get that bit replaced). If the nick is in the cable that goes from the PSU to the laptop endvthen you should be able to simply wrap some insulation tape around it to protect it from any further damage. (Not cellotape - its horrible stuff for that).