Car Battery Charging System

Hi,

I know similar kind of topics have been discussed time and again but I cant really get to the soul of 12 V car battery charging system. Can anyone please help me with these.

1. What should be the output voltage of a 12 V battery charging circuit??

2. How authentic is the information of battery's terminal voltage to determine the amount of charge battery still has, and what are its specifics like a completely discharged battery will indicate this voltage and a completely charged will show this..

3. Is a constant voltage-current limited supply better or a constant voltage-constant current supply good for charging the battery??

4. Does increasing the amount of current forcefully charges the battery quickly??

Answers will be highly appreciated.
Thank you.

P.S. I have googled about batteries and their charging quiet alot but havent really found specifics.

For ultra long life of a lead acid battery the charging voltage should be 13.8 V.
1. The charging voltage is a trade off between charge time and battery life. Modern Chryslers using 15V!!!!!
2. The voltage is an indicator of the chemical activity, charge is that and the AMOUNT of the chemical activity, i.e. area of the plates that are active.
3. Its the current that causes the chemical change, the voltage is required to get the current in.
4. Yes, the big problem is over heating the internal plates. this is why the current should be as low as possible. telephone lead acids are huge = 1m X 1m X 1m per CELL(!) but are only charges at .05 A, but they last 50 years.
Frank