you just bluntly ignored fact, plain and simple should you use a silver calcium battery your alternator needs to charge at a higher rate too, knowing the difference between those batteries has got nothing to do with anything.
yes older cars draw less from the battery but that doesn't compensate for not having the required voltage in the first place.
@YoungRedNed replace the calcium batt with a normal willard lead acid battery and watch your problems disappear. my willard is going on 3 years now and the silver calcium in my Ford Fiesta is going on 6 years now..
Ive been in the battery/auto electrical business for 10 years, and do you think that your 3 years experience with 1 battery makes you an expert?
What you take out, you need to put back. If you take less you need to put back less. Do you understand that? You can charge a silver calcium battery with 3 volts if you have enough time and you're not drawing anything at the same time.
Anyone who tells you that you can't use a silver calcium battery because your alternator does not charge enough is a moron.
Oh and by the way, ALL Willard (and Sabat) batteries are silver calcium. To run a totally separate line to make old tech is just too expensive (and plain stupid).