I am running an Arduino nano, 2 HC-SR04 ultrasonic sensors, and a 7-segment display off of 4 AA batteries. It is a simple device, when one sensor detects a close object it increments the counter by 1, when the other object detects something it decreases it by 1. The display is set to blink, off for 4 seconds then on for 0.5 seconds in order to conserve battery life.
This works great for the first few hours, however, I notice after a couple of hours when the display is on "0" or "8" the number flashes for like 0.1s and then off. There is nothing in the program that should make it do this, and it works as intended for the first few hours, which leads me to believe it is a battery-related issue.
When displaying an "8", the system uses around 200mA, when the battery gets low could this cause it to just require more current than the low batteries can consume? Or what could cause this problem perhaps? The AA rechargeable batteries are marked as 2700mAh, even running at a constant 200mAh without the display blinking it should reach around 13 hours give or take I believe. Currently, this seems to happen around 3-5 hours of running