Can overcharing your cell phone damage it?

I think so because I believe when you charge, heat is transferred, and if it is being overcharged the heat would no longer be accommodated by the atoms inside charger and if it happens the probability of it expanding would manifest in the physical structure of the battery thus destroying the battery in the process.

definitely it won't affect your cellphone much.......but, it affects slowly.....

It is recommended to avoid overcharging any type of rechargeable battery. It does not damage the phone, but shortens the life of the battery. I usually try to unplug it once it is fully charged, though I have forgotten it over night a couple of times.

i don't know but i leave mine on the charger all the time, very seldon ever use it.

it happens in rare case if a battery is not of standard quality....in some nokia phones this problem was seen the battery was bl-5c and many of those batteries where replaced free of cost by the company!! I keep my cell charging n sleep...nev faced any damage touch wood!!

I don't think overcharging the battery hurts the phone itself, but it will wreck havoc on your battery. If you overcharge your battery, it will cause the battery to not stay charged for a very long time. Therefore, you would probably have to buy a new battery. The way to change this is: 1) When you buy a new phone, charge the battery for as long as the manual says. Taking it off any earlier ruins the battery. 2) Only charge your phone when it is about to die. If you always put it on the charger at night, even when it's a full battery, it overcharges the battery. (I've made this mistake before). Cell phones need to be taken care of like anything else in the world. Without a battery, it's just a piece of whatever it is made of.