Since I’m starting to use more 9V rechargeable batteries, I thought it would be a good idea to build a simple 9V rechargeable battery for my friendly guitarist instead of having to urge him to look ...

Dual-voltage power supply is required especially for powering the op-amps and some of the instrumentation amplifiers. A few low-power audio pre-amplifiers also use dual-voltage supply. This circuit ...

Batteries don't output a fixed amount of current. The current varies with the load. The ratings of the batteries you are describing are probably the maximum currents. As long as the load is below the ...