SG90 Servo power and control

Hi folks,

I just want some advice on if what i'm planning on is an OK thing to do...

I want to use a lipo battery to power two servos that will be controlled by a liylpad simple. This will mean that the servos supply line will be around 3.7V but the control signals will be 3.3V since the power supply on the board is regulated.

Will the difference in voltages cause any issues with the servos?

That's pretty low supply voltage for a servo - are you sure they will run? This would seem to indicate 4.8V is needed, which not even a fully charged LiPo can supply.

I read that it had an operating range down to 3V.

here is the info I read:

I could also use an HXT900 which every datasheet I can find say the voltage range is 3V to 6V. So assuming this is the case, is the control voltage being lower an issue?

You should be o.k. on a single Lipo, I've run SG90s like that. They're obviously a bit slow but they work.

I don't think the 3.3V signal will be a problem but I've never actually tested that.


Thank you Steve! I don't need need high speed so I hope this will do the trick! I have the servos, i'm just waiting for my JST connector splitters to arrive then I can test over the weekend.


I tested the two servo's using the lilypad simple and 1 x 3.7V lipo battery and it worked fine.

The servo's buzz if the battery is discharged so i'll probably wire two up in parallel to give me a bit more life between charges. Otherwise it all looks good.