I needed to figure out exactly how much power the airsoft guns actually use. Voltage is pretty straightforward: the battery's nominal voltage is 11,1V so under load it will probably be a bit below that.
Current, however, is rather more difficult to measure. My multimeter is only good up to 10A and I expect higher current than that.
Luckily, I have data loggers on two of my remote controlled helicopters which are also electrically powered and run on 37V batteries up to 80A (yes, that is a lot) so they should be perfect.
So I went and connected the guns to one side of the data logger and the battery to the other, plugged in the USB lead, started the application and set it to live recording. Here are the results.
First the M110 gun:
And here the M130 gun:
The first shot draws significantly more current than the rest. This is seen clearly both when firing on semi-auto and on full-auto.
The M130 gun draws more current but not a lot more.
Based on these measurements I settled on a maximum current of 60A and a continous current of 20A.
This is the kind of data logger I use: Eagle Tree eLogger