You really can't calculate that, it's determined at manufacture. It'll be stated on the battery casing. Look for something saying Ah, Ampere hours.
Yes, it will hold it's charge for at least 6 months in storage if it is a very good battery to start with.
Battery is getting old and will not hold a charge or there is a drain on it. Battery is getting old and will not hold a charge or there is a drain on it.
If it has a dead cell the battery will not hold a charge and must be replaced.
no
The most common reason is one of the cells in the battery is bad and the only thing to do is get a new battery
A good auto battery will hold it's charge for at least 6 months or longer.
The cold weather slows down the chemical reaction that goes on inside the battery.
It sounds like the alternator is bad. If the alternator is bad the battery will not hold charge when running
Either the alternator is not providing a charge to the battery, or the battery has a dead cell and won't hold a charge. There are auto parts stores (AutoZone, Advance, O'Reilly's) that will check batteries and/or alternators free of charge.
If your battery doesn't hold a charge while running then your alternator is bad
To charge a car battery you need aproximatly 8000 amps To charge a car battery you need aproximatly 8000 amps
Car battery acid goes everywhere; acid can burn the hands if the person is not careful. A battery that is low on acid will not hold a charge as well. Most new car batteries have "cells" which hold the acids, so it's likely one cell is leaking.