C172 RG electrical system Q

[citrus]

This is taken straight from the AFM, picking up from the second line under the "electrical system" section.

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The system uses a battery, located aft of the rear cabin wall, as the source of electrical energy and a belt-driven 60-amp alternator to maintain the battery's state of charge.
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I thought the battery was only used to crank the starter and provide back up power in the event of an alternator failure? Maybe I am confused but it seems like this is saying that the battery is THE source of electricity at all times?

 

[Blackhawk]

This is taken straight from the AFM, picking up from the second line under the "electrical system" section.

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The system uses a battery, located aft of the rear cabin wall, as the source of electrical energy and a belt-driven 60-amp alternator to maintain the battery's state of charge.
---------------------------------------------->

I thought the battery was only used to crank the starter and provide back up power in the event of an alternator failure? Maybe I am confused but it seems like this is saying that the battery is THE source of electricity at all times?

If it's the 12 volt system (can't remember my RG stuff), the battery must be working for the alternator to work.
http://ronkilber.tripod.com/alternat/alternat.htm

 

[rframe]

Mostly semantics. The battery is a capacitor that can act as a source of power, the alternator is a generating source of power, when both are on the system they are both providing power to anything drawing current.

Probably the simplest way to think of it is that the battery provides electricity and the alternator keeps the battery charged by working to maintain steady voltage on the bus. The alternator's output varies depending upon the bus voltage, so it is reactive to what the battery is already providing the system, in that sense I'd say the battery is the 'master' of sorts.