OK to power my Nano project with a 7.4v lipo?

I want to control by IR 2 mid size servos and also power some led strips from my Arduino Nano using only one power source. I have read conflicting opinions on using a lipo for the Arduino.

The data sheet says the Nano can take 7-12 volts, so in theory I can use a 2 or 3 cell lipo (7.4v/11.1v), probably around a 1000-2000mAh. What problems could I face?

I am a total noob at this but this it what I have built so far. I've only tried it with a 9v battery and it does work with one servo.

:sunglasses:

Don't power your servo THROUGH the nano. Using your diagram, connect the power to the breadboard and then power the nano and the servo from the breadboard.

If the LiPo is within the recommended voltage range for the Nano then the type of battery does not matter. Be careful to ensure a LiPo is not discharged too deeply as that damages them. Also use a proper LiPo charger as they can go on fire if mistreated.

...R

Bear in mind that a fully charged 3 cell (3S) lipo is 12.6V which is pushing your luck. But if you stick to 2 cell (2S) the Nano will be fine.

The only catch will then be that most servos are only specified up to about 6V. Even the full voltage of a 2S lipo is a bit too much for them. So what servos are you using ?

Steve

Thanks guys. If I power the Nano from the breadboard then the servos get too much power as they need 4.8v-6.0v. So I was thinking 5v from the Nano is perfect using a 2cell lipo. I will be adding another servo and some LEDs also. So if I with the 9v in the picture with a 7.4v lipo that will work yes? I'm just worried the scary lipo will damage the Arduino?

Robin2:
Don't power your servo THROUGH the nano. Using your diagram, connect the power to the breadboard and then power the nano and the servo from the breadboard.

If the LiPo is within the recommended voltage range for the Nano then the type of battery does not matter. Be careful to ensure a LiPo is not discharged too deeply as that damages them. Also use a proper LiPo charger as they can go on fire if mistreated.

...R

slipstick:
Bear in mind that a fully charged 3 cell (3S) lipo is 12.6V which is pushing your luck. But if you stick to 2 cell (2S) the Nano will be fine.

The only catch will then be that most servos are only specified up to about 6V. Even the full voltage of a 2S lipo is a bit too much for them. So what servos are you using ?

Steve

lifeofbrian:
Thanks guys. If I power the Nano from the breadboard then the servos get too much power as they need 4.8v-6.0v. So I was thinking 5v from the Nano is perfect using a 2cell lipo.

I understand the problem of the battery voltage being too high for the servos but your must NOT use the Nano's voltage regulator to solve the problem. Use a separate 5v regulator for the servos - for example a 7805 voltage regulator IC.

...R

Thanks Robin. What is it I'm trying to avoid here? Is it that the Arduino cannot take the lipo power, or not push it back out for the servos?

Would I connect the lipo to the Arduino from the breadboard in the same way, GND/VIN?

Would I need to regulate the power from the lipo to the Arduino?

Sry I'm such a noob lol.

Robin2:
I understand the problem of the battery voltage being too high for the servos but your must NOT use the Nano's voltage regulator to solve the problem. Use a separate 5v regulator for the servos - for example a 7805 voltage regulator IC.

...R

lifeofbrian:
Thanks Robin. What is it I'm trying to avoid here? Is it that the Arduino cannot take the lipo power, or not push it back out for the servos?

An Arduino is not able to supply enough current on its 5v pin to drive a motor.

...R

Probably the simplest solution is to get a switching DC-DC (buck) converter to step the lipo voltage down to 5V and use that to drive both the servos directly and the Nano (through the 5V pin).

Steve

Hi All,

I have a similar issue with my project, actually is not an issue is more like a wonder...

So I've decided to run lipo 7.4v to my NANO and then will attach 6v siren which can handle 8v as well, so no issue with that.

Then I will connect lipo to NANO VIN and GND, and SIREN's GND will be connected direct to lipo (same as NANO) and VIN will be connected to the relay then lipo.

When I'm running siren and NANO from the same power source 7.4v lipo, should I consider to attach something else? Like ferrite rings or condensators so there will not be any interference or power drops?

I've tested my project already and it is working fine, just a bit not sure about long term?

And is that kind of simple connection is not dodgy?

Thanks!

umm....why not add a small value resistor between the batery and the arduino board?!few Ohms will do the trick...drop the initial 12,6 V (the fully charged up battery) to somewhere below 10 Volts ?!of course u can calculate a more precise value of the resistor but i suspect this will drain the battery faster