# Wierd behavior on circuit

Hello,

I recently finished a project and decided to try running my stepper motor 12V 1.3A through a fully charged battery of 4.2V boosted through DC - DC booster to 12.5V and relay started to turn on and off every second, but if the USB from the PC is connect to the arduino everything works normally, I uploaded the video of what is going on hopefully that will be more clearble than my words and hopefully someone could help me clarify why isn't it working with battery only?

Welcome to the Forum. You have not given us nearly enough information to help you solve your problem. It is important to provide as much of the information that is needed to solve your problem as you can, in your first posts. The forum link above has guidelines for posting in a standard way that makes it easiest for people to provide you with useful answers. Making an effort to do this will greatly increase the number and quality of helpful responses that you get. Please read this post:

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With a circuit, the most important piece of information is the schematic.

If the Arduino's voltage regulator is dropping 12.5V to 5V (7.5V drop) it can only output about 125mA without overheating and shutting down. What is your total 5V current load?

JCA34F:
If the Arduino's voltage regulator is dropping 12.5V to 5V (7.5V drop) it can only output about 125mA without overheating and shutting down. What is your total 5V current load?

Hi,

I have switch, photoresistor, driver A4988, relay module all sitting on 5V, I will post a schematic made in fritzing in a minute, might help out more, or its just that all of these components require more mA than I am actually providing?

Lowering voltage down to 10V did the job actually, could you tell me what kind of problems could that cause to stepper motor if it operates on 12V and I'm operating it on 10V? operations are short tho, approximately 10 seconds every 5-6 hours

Red lines would represent "5V/12V" black "GND" yellow "signal for arduino" brown "analog signal"