A battery serving as a voltage regulator - not as a power source.

[Vinyasi]

Since Andre wants me to not clutter up my original message thread with off-topic chatter, I've started this thread in hopes of satisfying his request.

I will base this message thread on one bullet point from my last post from that thread ...

A battery is a good example of a power supply which is not acting as a power supply. In this linked example, it is acting as a voltage regulator capping its parallel contribution to a circuit at the battery's rated voltage. This battery does not have to contribute any amperage, in the form of amp-hours, to power a circuit connected to this battery in series with the remainder of this circuit. It could, instead, be charged by this circuit (namely, topped off with a very weak charging current). This will insure the survival of this battery's charge for a very long time while insuring that this circuit can also be powered for a very long time on this battery's voltage, alone.

Hence, this circuit can't run down nor can its battery, either, since no amperage is consumed by the circuit. It produces amperage sufficient to power its inductive load plus top off the pair of six volt batteries.

It accomplishes this due to not consuming any amperage. It accumulates volts.

 

[FvM]

I preliminarily approved the thread although it doesn't manage to ask a question on it's own. Please clarify your question.

Batteries used as voltage regulators or voltage reference are known since more than hundred years. Review the keyword "standard cell".

Most battery applications are however related to sourcing power.