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Arduino servos not being supplied enough power by 9V battery? Answered

Hey guys, I'm working on my first instructable which is an robotic snake which you control via the HC-06 bluetooth module and an arduino. I'm using an arduino bluetooth app on my smartphone, but this isn't the problem. There are three servos which I am supplying power to, two continuous rotation servos for movement and one ordinary servo. I'm powering it through a 9V battery thing I got off of the adafruit store, which has the plug that goes into the power supply. When I try to control it like this, the servos twitch and barely move. The ordinary one doesn't as far as I can tell. However, when I supply power through my computer cable, the bluetooth still works from my phone, and the servos go at an ordinary rate. I'm supplying the two continuous rotation servos and the normal one through the 5 volt pin, and the bluetooth module through the 3.3 volt one. Can anyone tell me why it isn't working, or an alternate technique of powering it?



3 years ago

Servo's may need a lot of current when accelerating and turning fast, esp. under load. A 9V battery is not a suitable power source, and a 1A USB might be enough. Preferably 4-6AA batteries to the power input jack on the arduino, and have the red wires on the servo go directly to 4AA, or a seperate 5V buck converter.

Thanks! I'll try this out soon.

Be sure to buy the rechargable ones !

6 in series will give you 9V at 2500 mah VS 900 someodd mah for a common 9V