Series or Parallel for Batteries

[jeffmylife]

I built a B40a kit a few years ago and recently started having problems. Since I first wired it up, I've had my two 9V batteries wired in parallel (both reds connected to + on the board, both blacks to -). It just occurred to me that if the electronics are truly 18V, the batteries should be in series. Can anybody confirm or deny this thought? I don't know if it would have caused my problems or if changing it would fix them, but I would like to make sure I'm doing it right when I get my bass back on its feet.

[amon]

I only know about wiring batteries for EMG's. Series yields 18v and higher headroom for the pickup (supposedly EMG's will take 27v, but I've never tried it), while parallel yields 9v and longer battery life. If the board requires 18v, you're starving it for power having batteries wired in parallel.

[jeffmylife]

For any future people who find this thread, I talked to the head guitar tech to make sure I hooked up a new electronics unit correctly, and the answer is series. Battery 1 black to Battery 2 red, Battery 1 red to board (+), Battery 2 black to board (-).