# Low battery indicator **URL:** \ **Category:** General Guidance\ **Created:** [March 30, 2023, 10:30pm UTC](https://forum.arduino.cc/t/low-battery-indicator/1109057 "2023-03-30T22:30:54Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![spiros99](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/spiros99/32/939829_2.png) [@spiros99](https://forum.arduino.cc/u/spiros99)\ **Post date:** [March 30, 2023, 10:30pm UTC](https://forum.arduino.cc/t/low-battery-indicator/1109057/1 "2023-03-30T22:30:54Z")
Hello, I have an arduino nano 33 BLE and i read accelerometer and gyroscope data from it and i classify them with machine learning to different activities. I have an rgb led that is turned on every time i do a specific activity. I would like to ask if it is possible to make another led turned on every time the battery is getting lower, with a 9v battery, connected to the vin pin. I know this battery is not the best option but i use it because its easier. I have found this circuit for arduino uno: > **[Arduino Battery Voltage Indicator](https://www.instructables.com/Arduino-Battery-Voltage-Indicator/)** > > Arduino Battery Voltage Indicator: When we are using a battery powered Arduino such as RC robots or Temperature Controller, we might want to check the battery voltage if it needs to be charged or replaced. It happens to me with my RC Panzer.... Can i use the same to my arduino nano 33 BLE or is there any case that i will burn it? Is it safe enough? ---
**Author:** ![anon94801460](https://avatars.discourse-cdn.com/v4/letter/a/278dde/32.png) [@anon94801460](https://forum.arduino.cc/u/anon94801460)\ **Post date:** [March 30, 2023, 11:07pm UTC](https://forum.arduino.cc/t/low-battery-indicator/1109057/2 "2023-03-30T23:07:06Z")
Most people would use a simple resistive voltage divider to reduce the battery voltage to be within the range of the Nano 33 ADC. 22K + 10K for a reduction ratio of 10/32 would be fine for a 9V battery, but you might want to calibrate it if you use standard tolerance resistors. For lower power drain use 220K + 100K, but add a 10 nF capacitor from ADC input to GND. ---
**Author:** ![TomGeorge](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/tomgeorge/32/215261_2.png) [@TomGeorge](https://forum.arduino.cc/u/TomGeorge)\ **Post date:** [March 31, 2023, 9:19am UTC](https://forum.arduino.cc/t/low-battery-indicator/1109057/3 "2023-03-31T09:19:07Z")
Hi, @spiros99 Welcome to the forum. > [@How to get the best out of this forum](https://forum.arduino.cc/t/how-to-get-the-best-out-of-this-forum/679966): > > See also [FAQ - Arduino Forum](https://forum.arduino.cc/faq) for general rules on forum behaviour and etiquette. Hello, Welcome to the Arduino Forum. This guide explains how to get the best out of this forum. Please read and follow the instructions below. Being new here you might think this is having rules for the sake of rules, but that is not the case. If you don’t follow the guidelines all that happens is there is a long exchange of posts while we try to get you to tell us what we need in order to help you, which is fru… Can you please tell us your electronics, programming, arduino, hardware experience? You need to Google; > potential dividers arduino Thanks.. Tom.. πŸ˜ƒ πŸ‘ β˜• πŸ‡¦πŸ‡Ί ---
**Author:** ![spiros99](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/spiros99/32/939829_2.png) [@spiros99](https://forum.arduino.cc/u/spiros99)\ **Post date:** [March 31, 2023, 10:18am UTC](https://forum.arduino.cc/t/low-battery-indicator/1109057/4 "2023-03-31T10:18:43Z")
Thank you very much! It really helped me πŸ˜„ ---
**Author:** ![JohnLincoln](https://avatars.discourse-cdn.com/v4/letter/j/7ba0ec/32.png) [@JohnLincoln](https://forum.arduino.cc/u/JohnLincoln)\ **Post date:** [March 31, 2023, 1:10pm UTC](https://forum.arduino.cc/t/low-battery-indicator/1109057/5 "2023-03-31T13:10:39Z")
When it is time to put the LED on, make it blink with a low duty cycle. That way you don't fully deplete your ailing battery so quickly. ---
**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:** [September 27, 2023, 1:10pm UTC](https://forum.arduino.cc/t/low-battery-indicator/1109057/6 "2023-09-27T13:10:54Z")
Closed on September 27, 2023, 1:10pm UTC This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.