The battery is not chargeable, so you have to replace it. The battery lasts anywhere from 6-18 months depending on usage so you don´t need to replace it often.
Yes, they will be charged; anyone who calls your 900 phone number will be charged. The person who pays the bills for the phone number calling will be charged.
If you look at the group numbers of non-transition metals, they can tell you charges. For example, Chlorine (Cl) is in group 17 (7A). This tells me that there are...
If the battery was working well when disconnected, then either its connections are dirty or a cable is about to break off. I mention the cable because disconnecting often can...