encryptor:
What is the max current I could draw from a 9V battery? I'm looking to draw 150 mA aka 0.15A from a power source. Does a 12V battery have a higher current rating? :~
Depends on the specific battery you are talking about. A 12vdc lead acid car battery can supply a lot more continuous current then a much smaller 12 volt battery. Small 9 volt batteries are designed to power smoke alarms for a couple of years but won't supply 150ma for even a day.
Lefty