Ok Tesseract - good link post...
But I differ on the 14.4V issue....
In fact I think all of you are hung up on this algorithm math..
The math is simple...
Automotive Batteries flaot charge - meaning the 13.8V from the alternator supplies the initiative to energize and charge the batteries. This also applies to deep cycle batteries (even when you have two 6V deep cycle batteries in series).
14.6V is the gassing off point where the electrolyte will gass off (it boils the electrolyte). In Solar Power
this is the process or normalizing or equalizing the batteries.
The only time you would use 14.4V would be in a large industrial tractor where you have four batteries parralelled.
As to the current at charging...
The reason you see your auto battery charger decrease in current has little to do with the battery chargers current regulation. At 13.8VDC a flooded cell battery will only draw the current necessary to put the plate/electrolyte back into staisis. The more the battery is discharged, the more sulfates attached to the plates and the more imballanced the chemistry. There fore the battery will require less and less current as it approaches equilibrium (hence the math algorithm to figure the theoretical point of staisis versus state of charge).
If you battery is drawing 12-Amps or more continually - Then You have A dead Cell!!! 12-Amps will charge a 120-AHr Battery from near dead (at about 40% Depth of Discharge for a Deep Cycle Battery). This is why there are different Battery Caharge capacity Chargers for different Battery syatems.
Or if you want to simplify your EV Bayttery experimentation life? Buy one of these:
Then you will only need a 45-Amp Bridge Rectifier, and two large 250V Electrolytics to smooth out the ripples...
Wah Lah - you now have a 0-130VDC 35Amp Battery Charger....