# Arduino UNO power supply via 3S LiPo **URL:** \ **Category:** UNO R3\ **Created:** [September 3, 2025, 6:58pm UTC](https://forum.arduino.cc/t/arduino-uno-power-supply-via-3s-lipo/1405284 "2025-09-03T18:58:44Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![KnwLdgSeeker](https://avatars.discourse-cdn.com/v4/letter/k/91b2a8/32.png) [@KnwLdgSeeker](https://forum.arduino.cc/u/KnwLdgSeeker)\ **Post date:** [September 3, 2025, 6:58pm UTC](https://forum.arduino.cc/t/arduino-uno-power-supply-via-3s-lipo/1405284/1 "2025-09-03T18:58:44Z")
Hi everyone, I'm currently working on a quadrotor project using Arduino UNO R3 board as a flight controller, to do so, I'm using a 11.1V 3S LiPo battery for my drone and I'd like to use a LM2596 step down module to supply my board via this battery, so my question is : _Should I connect the LM2596 output to V in port or the DC Power Jack/USB port?_ ---
**Author:** ![sonofcy](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/sonofcy/32/1283617_2.png) [@sonofcy](https://forum.arduino.cc/u/sonofcy)\ **Post date:** [September 3, 2025, 7:10pm UTC](https://forum.arduino.cc/t/arduino-uno-power-supply-via-3s-lipo/1405284/2 "2025-09-03T19:10:08Z")
If you can use the DC Power Jack you don;t need the LM2596, the jack already has one. ---
**Author:** ![gilshultz](https://avatars.discourse-cdn.com/v4/letter/g/67e7ee/32.png) [@gilshultz](https://forum.arduino.cc/u/gilshultz)\ **Post date:** [September 3, 2025, 7:13pm UTC](https://forum.arduino.cc/t/arduino-uno-power-supply-via-3s-lipo/1405284/3 "2025-09-03T19:13:09Z")
Can you post an annotated schematic showing what you are going to connect to the UNO and to which pins. Show all external hardware and power sources. ---
**Author:** ![jim-p](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jim-p/32/922840_2.png) [@jim-p](https://forum.arduino.cc/u/jim-p)\ **Post date:** [September 3, 2025, 7:42pm UTC](https://forum.arduino.cc/t/arduino-uno-power-supply-via-3s-lipo/1405284/4 "2025-09-03T19:42:09Z")
> [@KnwLdgSeeker](#): > > _Should I connect the LM2596 output to V in port or the DC Power Jack/USB port?_ Set the buck to 9V and connect to either Vin or the barrel jack. ---
**Author:** ![JCA34F](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jca34f/32/340148_2.png) [@JCA34F](https://forum.arduino.cc/u/JCA34F)\ **Post date:** [September 3, 2025, 10:06pm UTC](https://forum.arduino.cc/t/arduino-uno-power-supply-via-3s-lipo/1405284/5 "2025-09-03T22:06:22Z")
What is the step down module's output voltage? ---
**Author:** ![KnwLdgSeeker](https://avatars.discourse-cdn.com/v4/letter/k/91b2a8/32.png) [@KnwLdgSeeker](https://forum.arduino.cc/u/KnwLdgSeeker)\ **Post date:** [September 4, 2025, 5:13pm UTC](https://forum.arduino.cc/t/arduino-uno-power-supply-via-3s-lipo/1405284/6 "2025-09-04T17:13:20Z")
Is it possible to connect the DC power jack to the step down output by regulating the output at 5V? ---
**Author:** ![KnwLdgSeeker](https://avatars.discourse-cdn.com/v4/letter/k/91b2a8/32.png) [@KnwLdgSeeker](https://forum.arduino.cc/u/KnwLdgSeeker)\ **Post date:** [September 4, 2025, 5:15pm UTC](https://forum.arduino.cc/t/arduino-uno-power-supply-via-3s-lipo/1405284/7 "2025-09-04T17:15:49Z")
![022fbff0feffb985ebaee34e066ac4dd59cef57a_2_500x285](https://europe1.discourse-cdn.com/arduino/original/4X/7/6/4/764d9aec81359f2c2c2520c62eae6e7858c05a2d.png) I'm using this Joop Brokking's schematic but I just want to add a LM2596 between LiPo and the Arduino Board in order to keep the board safe from eventual overheating or overvoltage and tht'a why I asked if I should use the Vin or 5V port to supply the board ---
**Author:** ![KnwLdgSeeker](https://avatars.discourse-cdn.com/v4/letter/k/91b2a8/32.png) [@KnwLdgSeeker](https://forum.arduino.cc/u/KnwLdgSeeker)\ **Post date:** [September 4, 2025, 5:17pm UTC](https://forum.arduino.cc/t/arduino-uno-power-supply-via-3s-lipo/1405284/8 "2025-09-04T17:17:02Z")
Thanks, are both case safe for the Arduino board? 🤔 ---
**Author:** ![KnwLdgSeeker](https://avatars.discourse-cdn.com/v4/letter/k/91b2a8/32.png) [@KnwLdgSeeker](https://forum.arduino.cc/u/KnwLdgSeeker)\ **Post date:** [September 4, 2025, 5:19pm UTC](https://forum.arduino.cc/t/arduino-uno-power-supply-via-3s-lipo/1405284/9 "2025-09-04T17:19:44Z")
Normally, the output is adjustable (from 1.25V to 35V) but I just want to know which voltage value is safe for the arduino board and to which port shoould I connect the step down's output ---
**Author:** ![sonofcy](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/sonofcy/32/1283617_2.png) [@sonofcy](https://forum.arduino.cc/u/sonofcy)\ **Post date:** [September 4, 2025, 5:27pm UTC](https://forum.arduino.cc/t/arduino-uno-power-supply-via-3s-lipo/1405284/10 "2025-09-04T17:27:31Z")
I would just connect the 11.1V to the jack, here is the spec ![Screenshot 2025-09-04 at 13.26.29](https://europe1.discourse-cdn.com/arduino/original/4X/1/5/d/15d99abd9ec1925d15be7834c014c041e9a6684d.png) ---
**Author:** ![jim-p](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jim-p/32/922840_2.png) [@jim-p](https://forum.arduino.cc/u/jim-p)\ **Post date:** [September 4, 2025, 6:11pm UTC](https://forum.arduino.cc/t/arduino-uno-power-supply-via-3s-lipo/1405284/11 "2025-09-04T18:11:57Z")
> [@KnwLdgSeeker](#): > > Thanks, are both case safe for the Arduino board? Yes ---
**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\ **Post date:** [March 3, 2026, 6:12pm UTC](https://forum.arduino.cc/t/arduino-uno-power-supply-via-3s-lipo/1405284/12 "2026-03-03T18:12:27Z")
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