Intercom with two stations hard wired

[AnalogKid]

Two batteries in direct parallel, with no regulating circuitry of any kind, usually is bad for the batteries. Which ever one has the lower voltage, even by millivolts, acts as a load on the other. This can shorten life enough to do something about it.

Yes on the schematic mod.

ak

 

[brockrwood]

Two batteries in direct parallel, with no regulating circuitry of any kind, usually is bad for the batteries. Which ever one has the lower voltage, even by millivolts, acts as a load on the other. This can shorten life enough to do something about it.

Yes on the schematic mod.

ak

I did not think about the differing voltages! Doh! In essence, the battery with the slightly higher voltage would try to "charge" the other battery, eh what?

Why a Schottky diode rather than a regular rectifier diode? I assume because the lower forward of the Schottky diode would have less of an effect on the voltage each battery can provide to the circuit?