Battery Terminolgy

Altenator sizes are in Amps Eg 80Amp. The volts are what the regulator is set to.

Ill have a crack...

Very simply put. There are two factors when charging, voltage difference, and ability to deliver power. Volts and amps.

A mains charger regulates the voltage to be correct to charge your battery, but is limited in the number of amps it can produce (before the volts drop), more expensive units (bigger) can produce more amps at the correct charge voltage = faster speed of charge.

So, mains charger speed to charge your battery dependent on its amp output. (assuming that volts are static)


Alternators are usually pretty big 80+ amps, so amps is not really a consideration for charging, since 20amps is about as fast as you want to charge a 100Ah AGM battery. Volts are. Some regulators are set high = fast charge, others low = slow charging.

So its really just that we talk about the variable given the situation and assume the other one is fine.

Hi Jeff,

This is how I explain electrical terminonlogy to people.

Volts/Amps explained

I was trying to type out my explanation but found it on the internet to save me taking half an hour to type it out for you. Poor typing skills here!
Hope this helps.

Cheers
Stu