I decided to take apart one of those cheap handheld fans. It takes 2AA Alkaline batteries. I wanted to hook it up to an arduino as a way to get into electronics, and I wanted to know what kind of battery would be best for the setup.
Hopefully, I measured the amps correctly, and it read out ~
.70 when the multimeter was set to 10 and @ DC current. So, the device has a 7A draw. From wikipedia, Alkaline batteries have about ~
1800mAh, so 2AA would give
So, total battery hours from 2AA would be
3600mAh/7000A = .514... which ends up being only half an hour.
If I wanted the setup that lasted roughly 2 hours, then that means I would need at least a 14000mhA battery without considering the arduino amp draw. That means I need at least 1 D battery or 8 AA batteries.
Does that seem right?