I tried to control 2 servos with my arduino. It worked fine but if I try to control 5 servos with my Arduino, it doesn't work. I want to power up the servos externally but I don't know how to do it. I'm using 5 push buttons and a pot knob to control the servos. And what battery should I use? And how to connect it with servo and Arduino?

The servo specs is:

  • Operating Voltage: 4.8-6.0V
  • PWM Input Range: Pulse Cycle 20±2ms, Positive Pulse 1~2ms
  • STD Direction: Counter Clockwise / Pulse Traveling 1500 to 1900µsec
  • Stall Torque: 3 Kgf.cm (41.3 oz/in) at 4.8V, 3.2 Kgf.cm (44 oz/in) at 6V
  • Operating Speed: 0.2 sec/ 60° at 4.8V, 0.18 sec/ 60° at 6V at no load
  • Weight: 38g (1.27 oz)
  • Size: 41.3*20.3*38.7*48.5*10
  • Plug Available: FUT, JR
  • Special Feature: Heavy Duty Plastic Gears, Economy Servo

What battery should I use to control 5 servos of above spec?

What should be spec of the battery?

  • 4
    \$\begingroup\$ "It didn't work"... consider this... if I went to the doctor and said I was ill, what could he diagnose from that? \$\endgroup\$
    – Andy aka
    Apr 3, 2014 at 9:12
  • \$\begingroup\$ They probably ran not fast enough, where not able to move anything or where stuttering. \$\endgroup\$
    – Veda
    Apr 3, 2014 at 9:26
  • \$\begingroup\$ what are the servos doing? what kind of loads will they have? will they pull huge stall currents and blow up a small power supply? I also think you have the wrong idea here - you couldnt control 5, the issue is CONTROL not power. But maybe you will find something else to control, and your question is specifically for powering. In that case, I say you should find a high current output 5V power supply somewhere, and power them all off that. \$\endgroup\$
    – KyranF
    Apr 3, 2014 at 10:10
  • \$\begingroup\$ In order to size the battery you are missing how much current you draw on average and for how long. \$\endgroup\$
    – Spoon
    Apr 3, 2014 at 12:10

1 Answer 1


Using my favorite search engine I found https://www.servocity.com/html/s9602_hi-speed_mg_bb.html It's a close match. However frustratingly the page does not contain the current required. So now you have to find the Data Sheet from Futaba in this case ... Which I could not find either....

So now I drop back on the Plan B and measured the current when loaded!

Take that value and multiply by the number of servo's

So whatever the total value is in Amps and you want it to run for an hour (Say 2A) then you need at least a capacity of 2Ah (Amp hours) at 4.8 to 6 Volts for your battery.

If you only want it to run for 30 minutes divide by 2 etc ...

Will it be exact, Probably not but good enough to get you up and running in the right direction.

Connect the battery negative to the Arduino The Battery positive to the servo positive only. Then the signal wire to the Arduino.

This is the simplist way, don't connect the Arduino positive to the servo battery positive as the servo will introduce a lot of noise and cause more problems (random resets and the like)

You can get round this with filters and regulators but that is more work.


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