If you reverse the connection of the battery charger you will discharge the battery. You may be able to correct the connection and charge it properly, or the battery may be ruined.
When it is charging the screen reads: Battery Charging. When it is fully charged it reads: Battery Charged.
The Alternator.
With the proper charging equipment, yes.
The Alternator.
it means it still charging, when fully charged that will turn into a cord plug
The Alternator.
Can You Charge...Yes. As a matter of fact, in order to charge a battery, the charging voltage HAS to be greater than the charged battery's voltage or no current will flow and charging cannot happen.Of course, the charging voltage cannot be excessive, or damage to the battery being charged will result.In your question, 4.6 volts is not excessive for a 4.2 volt battery.
NO, a 12 volt battery cannot be charged with a 6 volt charger. To charge any battery, the charging voltage has to be, at least, slightly higher than higher than the voltage of the battery. Current flowing through the battery is what accomplishes the charging, and no current will flow at or below the voltage of the battery to be charged.
Yes, rechargable batteries tend to get warmer when charged.
Altenator is not charging battery!!
The phone will go flat quickly. When charged it'll never switch from "charging" to "charged". Or it'll say that charging is complete real fast, even when starting from a flat battery.
Either the charging system has failed or the battery is bad.