Using 2 9V batteries

[jeff]

If one were to use two 9V batteries for a 18V source for a pedal, what would be the "correct way to wire them?

I drawn the original schematic then 3 options:
Wire the 2 9Vs in series and treat it as one 18V battery
Use one battery for the +rail, one for the -rail
Connect the batteries from VR to +, VR to -

My concern is if someone uses a fresh battery and a not so fresh battery. What would the concequences be on
 -the pedal
 -the batteries
for each?

Is there a correct way to do this?
(I'm not really concerned how we refrence this, weither we consider it 18V,9V(VR),0V OR +9V,0V,-9V, just how the batteries should be wired)

[sluckey]

If one were to use two 9V batteries for a 18V source for a pedal, what would be the "correct way to wire them?

Simple series.

[jojokeo]

Series w/out the caps and resistors is fine. Only need them if you are creating a 1/2 supply voltage reference for feeding op-amps for example. The batteries will seek an equillibrium whether you attach them in parallel or series. It's not the same as you may be thinking regarding when we use resistors across two filter caps in series to share the current load placed on them.

[super&plexi]

I have a harness I made for some of my pedal builds that does series connection so I can get life out of 4.5 "used" batteries. partly for the environment, and partly for my pocketbook. OK, mostly for wallet. gonna jump on the green movement,...patent the 2nd life landfill angle.