Asked — Edited
Resolved Resolved by Rich!

Old Ez Robot Servo Voltage Needs?

I have been looking through all the old posts and cant find any info anywhere anymore on what the old standard servos needed for voltage feed. I used to plug them right into the old V3 EZB and they ran nicely off the 5vdc it supplied.

Anyone know their max voltage?


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If memory serves me correctly they are Futuba s3003 servos rebadged. A quick search of the forum for Futuba should bring up a topic where it was mentioned (I haven't done this yet, I will once I finish this).

Edit: Yes I was correct. This topic DJ explains they are Futuba. In another Josh gives the model which is s3003.

If I am correct then the operating voltage is 4.8-6.0v according to this site (and a few others)


Don't know how you do it Rich. I looked for 1/2 hour for that post. Thanks


they will take up to 7.4 volts. keep in mind that they're pretty weak with plastic internals - so it's easy to overload them with too much weight. The original Revolution robots were actually built with the old ez-robot servos and used 7.4v lipo batteries - unregulated.

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That's great to know. I was tempted to try it but it turns out I am too chicken to :)


Great news D.J., I was glad to find out that the standard EZ Robot servos worked on the original Revolution Robots using 7.4 volt lipo batteries. I have wondered what voltage max range they would take? My question is, am I correct in thinking my rechargeable Radio Shack (six C size) R/C pack 7.2 volt Ni-Cd battery packs will work on my current Robot Captain Ann Droid when I receive my EZB 4 without regulators? She has 10 standard EZB3 kit servos. I know there are distinct discharge rates and voltage advantages to different types of batteries. I understand sensors may need a regulators. This was a very helpful thread! Thank you Dave. Keep sharing and asking. Steve S :)


@Steve S, Ni-Cd's should work fine, but be aware of the power fall-off. Ni-Cd hold fairly steady voltage as they discharge, then suddenly drop to near 0. You may have little to no warning that you are about to lose power unlike NiMH, LiON, and LiPo which all fall off more gradually.



thetechguru, Thank you for responding. Currently I operate my robot for over 30 + minutes with the Ni Cd pack. One extra pack also. I also have a Radio Shack 7.2 volt Ni-MH that I have not tried yet? I was afraid I would have to buy many regulators to upgrade her to take full advantage of her IRobot Create platform send and receive serial, (already does great, calculates angles, distance, and tones with EZB3). So much to look forward to. Steve S