(published on 10/22/2007)
(published on 05/11/2008)
Most circuits are just fine with a big battery at the right voltage. The resistance of the circuit automatically limits the current when the right voltage is applied.
Occasionally there's a slightly different situation. Some of those cheap plug-in DC supplies that come with electronic devices are designed to put out the right voltage only when hooked to a device that drains the right current. If the drain is too low, the voltage drifts up some. Batteries aren't like that, however. Their maximum voltage is just a little above the rated voltage, well within the tolerable range for the circuit.
Mike W.
posted without vetting until Lee returns from the Serengeti
(published on 10/28/2014)