I have five Futaba S3003 servo motors. I want to run them simultaneously. What battery should I use?

The datasheet says:

  • Current drain (4.8V): 7.2mA/idle
  • Current drain (6.0V): 8mA/idle

I'm not sure if the ampere value is right. I think it is too low.

Can someone tell me what power source I should use?

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    \$\begingroup\$ It is the energy when in use you should evaluate. \$\endgroup\$
    – Solar Mike
    Apr 27, 2022 at 10:28
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    \$\begingroup\$ ”I think it is too low." Yes, it's only the current at idle. The current when operating will be higher but the datasheet doesn't give any guidance on what that will be. The operating current will vary with the mechanical load so a data sheet can only provide you with a rough guide. (Current at stall torque would have been handy though.) As you say you already have them you may as well hook them up to their intended load and measure the supply current. \$\endgroup\$
    – Graham Nye
    Apr 27, 2022 at 10:31
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    \$\begingroup\$ You should also consider the duty cycle as well as the load. The answer will be different if they are moving near-continuously compared to brief bursts of movement then long idle times. Then you need to think about how long you want it to run for between charges/battery changes \$\endgroup\$
    – Chris H
    Apr 27, 2022 at 10:41
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    \$\begingroup\$ You could measure how much current one of them uses when stalled (prevented from rotating) as this will be the maximum possible current usage. \$\endgroup\$
    – user253751
    Apr 27, 2022 at 10:48
  • \$\begingroup\$ Is this DC Adapter will be enough? amazon.eg/-/en/Generic-2725602393463-6V-Power-Adapter/dp/… \$\endgroup\$ Apr 27, 2022 at 10:59

1 Answer 1


I would go for 7.2 Volt Lithium battery or 2 x 3.7V lithium cells in series additional 1.2 volts wont cause any harm. purely for servos. Secondly 8 milli amperes is listed as idle current which is fine. these servos draw around 250ma at peak load so 5x250 = 1.25 amps for all 5 motors , that is your minimum current you need to run these for an hour. depending on your needs of how long you want them to run on battery , you will need to choose your battery capacity. you could also go for 6V lead battery if you are ok with the size.

  • \$\begingroup\$ Thanks! That's helpful. Is this DC Adapter will be enough? amazon.eg/-/en/Generic-2725602393463-6V-Power-Adapter/dp/… \$\endgroup\$ Apr 27, 2022 at 11:01
  • \$\begingroup\$ It would be enough, but if you are controlling these servos with some electronics then you should consider what current consumption that electronics will have (if that electronics is sharing same supply). In general it should be ok because your servos can still run at lower voltages too. \$\endgroup\$
    – Gurpreet
    Apr 27, 2022 at 12:17

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