Rechargeable 9v batteries for fx pedals

[flester]

Are Rechargeable 9v batteries a viable option for pedals?

Just asking cos I have some, and I broke my fx power supply. The ones I have claim 350 mAh capacity but interestingly the only major brand ones I can find are Duracell with 170 mAh. Are the claimed mAh values reliable in your experience?

[Loudthud]

How old are the batteries ? Are they Ni-Cad or some other chemistry ?

Some rechargeables can be problematic. They might not charge up to rated Voltage or hold rated maH. Many times one cell will be weak and may take on a reverse charge as the battery discharges.

[flester]

The ones I have are a few years old and Ni-Cad. I was using them to power a TDA2003 amp drawing up to 500mA. My hungriest battery driven pedal draws 30mA and the rest are single figures.

Maybe I just need a newer set of batteries. Worst case I leave a pedal powered on overnight and need a new battery.