Originally posted by distudio Interesting, they quote using a 0.01ohm shunt resistance (which I indecently have at my disposal), that bulletin was from 2005, it probably relates to NiCd chemistry (note it's not specific regarding chemistry). I still doubt it's a good idea to treat NiMH Hybrid type cells this way, a 1 ohm would suffice and would be a far more representative maximum instantaneous load in the case of a DSLR, and this is what I use (I have a small jig with test button set up), but I'm just an electronics engineer.
I would not disagree that "Flash Amps" is unkind to batteries - if done repeatedly or over a longer duration, and should
NOT be used for Li-Ion (where it probably is dangerous).
But it is called "Flash" Amps because it is supposed to be done quickly kind of like an instantaneous reading.
0.01 ohm resistors are fairly uncommon (eg: A little less than 2 feet of 14 AWG wire has a resistance of 0.01 Ohms)
so most people just use a DMM directly relying on the meter's own resistance -
it's not a "precise" measurement - but merely a quick way of checking a battery's health.
However it is pretty common practice for NiMH which has been around for many years - without reports of problems, at least to my knowledge
CPF has a thread where some tried to explain
Flash Amps EDIT to ADD -
Flash Amps is also called "Burst rating" for batteries.