These colors indicate the charge:
Red = Needs Charge.
Why is my cart battery blinking red?
If your battery reads too low, the device will blink red and shut down. If your device overheats, it will blink three times before turning off. In the case of a short circuit, the mod will turn the device off automatically.
Vape Pen Blinking RED
If the pen blinks red when vaping, it's a sign your battery is going low (below 30%), and it's time to recharge it. On the other hand, if the red or another color blinking happens when charging the pen, it simply means that the charging is happening.