Does the rechargeable battery end up charging scrap?

My laptop is connected 24/7 to the power supply, except when I shut it down. I unplug the power adapter. Otherwise, the laptop is even when it is fully charged s.Partner is harmful for the battery?

Can be harmful, it does not necessarily have to. It is best to only charge it up, if need be. Had earlier done the same thing with my old and after 2 years about the battery went on the road then super fast empty.

But it can't explode or?

That's not how you should use a Li-Ion battery. So do not wonder if the battery is no good after a few years. But he will not explode.

Normally the charging electronics will switch off as soon as they detect that the battery is full. However, the shutdown can break, and then the battery can explode; that is very rare.

It is also said that you should operate Li-polymer batteries as possible between 10 and 90% charge, but I did not quite understand why, or why the built-in electronics does not provide.

I also run my laptop as well - except on the go - and have not noticed any problems yet. (However, I let it run on battery every half year until it shuts off.)

Even if it is recommended to recharge the battery to 90% before using it for a longer period of time and then remove it. (Store in a cool and dry place)

That's why it does not explode with 99.9999% probability. Something else has to happen, such as overheating, strong mechanical shocks or the like.