Two questions if may ...How does one know when the battery charging is complete ?
That’s a common question asking in many forums. After a battery full charged condition if you measure the charging current it will be nearly to ZERO in some charges. Most of these are constant voltage/current limited type. When the battery voltage comes to the adjusted value it will limit the charging current & maintaining the battery voltage. There is a diagram in your datasheet also.
Some chargers called constant current type ones. With this type charges the battery will charge with the calculated charging current but it will not maintain the batteries terminal voltage. It will exceed the terminal voltage to overcharge condition.So all the time you have to check whether its overcharging.
If you want to stop the charging after battery is full charged condition then a COMPARATOR can do the job. When the battery voltage EXCEEDS the comparators ADJUSTED voltage, the comparator output will stop the charging by making output low or high.
But good charger manufactures they won’t suddenly TERMINATE the charging when it’s reached to maximum calculated value, they will look over & over again & switching to very low charging rate & finally terminate the charging.
These are the basic charging termination methods. Also there is TEMPERATURE sensing, internal PRESSURE sensing charges as well. They are too complicated.
Also MAXIM has introduced some charge control IC’s as well but it will well supported to NIMH batteries.
Also it doesn't specify if this is for lead acid types (i guess a car battery is lead acid type) or gel cells ?
Most car batteries (but not all) are lead acid batteries.
The term SEALED LEAD ACID commonly used to refer to either Gel Cell or AGM batteries.
The LM317T version works well for me. If you need a high current version then LM350 can do the job.
Also I have seen some CAR CHARGER circuits they used just the Transformer + Diodes + Capacitor + Ammeter
When the battery is not charged, the ammeter reading shows some amps.
When the battery is fully charged the ammeter reads Zero or nearly zero, after which the battery should be removed from the charger.