Hey everyone!
I'm building a project that requires me to run 5 servos with an Arduino. AA batteries are a bad idea so I went to a local hobby store and asked them for a suitable battery. They recommended a black, box type 12V battery pack (its LiPo or NiMn I guess) for 5 servos. I'm concerned I might burn the servos because they're rated 4-5-6V and the source is 12V. The store owner said it'll work fine because I'll be using 5 servos together. Is he correct?
With that much current being drawn, would my normal jumper wires and breadboard hold up?
Thanks for your time.
No, you cannot run 6v max servos with 12v, they will die pretty much immediately. You will need a voltage regulator. Or a lower voltage (4-6v) battery pack.
The battery type is critical to know before buying it. If you don't know why you are buying it and how you will charge it then stop right there.
I can't give any more advice without some info on your servos.
You can use a BEC to power those from 12v. Your hobby store should have recommended that.
Google battery eliminator circuit.
SurferTim:
battery eliminator circuit.
Correct - but not the sort of thing that would jump into the mind of a newbie who wants to use a battery 
The term "BEC" means (for electric model airplanes) eliminating a second battery just to power the servos and the receiver.
...R
Thanks for your response.
I'm using Futaba s3003 and MG996R servos.
I purchased a 4V lead acid battery pack that gives 2A. How many servos can I run off this?
The shop only had 4V, 8V and 12V battery packs. Will the 4V do even though the servos need 4.5V?
The usual sizes of lead acid battery are 6v and 12v.
I suspect 4v may be on the low side - but it probably won't do any harm to try. if you have the option of returning the 4v battery or a refund I would take it and buy a 6v battery somewhere else.
I also suspect you mean 2Ah (the capacity of the battery) because lead-acid batteries can usually produce lots more than 2 amps for a short period of time.
...R
Keep in mind that a freshly charged 6 volt lead acid battery can be almost up to 7 volts (for a short time). Test the battery with a multimeter when it comes off the charger. Servo electronics are pretty sensitive to over voltage.
Hello, for a prosthetic arm project that uses 5 servo motors ( tower pro SG90 micro servo 5V operating voltage) i have a 12V 2400mah Li-ion battery how can i use it to power all 5 servo motor. Can i use the same battery to power all my servos along with my arduino uno board or i need a seperate power supply for it ? If in case i can use the same battery how long would it last?
Someone kindly reply ASAP its quite urgent.
thankyou.
No you cannot run 5V servos direct from a 12V battery. You need a DC-DC converter with at least a 3A or 4A output to reduce the voltage to 5V. Then you can run the servos and the Arduino from that.
How long a battery charge will last depends on how much the servos are used and how efficient the converter is.
Steve
Thank you for your help. one more thing can you suggest an appropriate DC-DC convertor for this purpose that you know or have used.
this will be very helpful
You can use a 12V battery but with a little engineering on your end. First determine the worse case current draw of the servos operating. Multiply that by at least 1.3 (safety margin) Then go on line and get either a Sepic or Buck Converter. The buck is the most cost effective. They are small and in the 80% + range in efficiency. The higher the efficiency the longer the battery life. They are available for less then a dollar for a 3A surge about 1.6 Amp continuous unit. That is the first unit I found on ebay searching for buck converter. They are small and light.
Have fun,
Gil