---
title: "Understand the LED colors - e355"
url: "https://docs.adyen.com/point-of-sale/user-manuals/terminal-deprecation/e355-user-manual/understand-the-led-colors-e355"
source_url: "https://docs.adyen.com/point-of-sale/user-manuals/terminal-deprecation/e355-user-manual/understand-the-led-colors-e355.md"
canonical: "https://docs.adyen.com/point-of-sale/user-manuals/terminal-deprecation/e355-user-manual/understand-the-led-colors-e355"
last_modified: "2021-02-01T15:20:00+01:00"
language: "en"
---

# Understand the LED colors - e355

[View source](/point-of-sale/user-manuals/terminal-deprecation/e355-user-manual/understand-the-led-colors-e355.md)

LED lights are used to communicate the status of your terminal.

***

| **LED behavior**                                                                      | **Status**                                                   |
| ------------------------------------------------------------------------------------- | ------------------------------------------------------------ |
| Green, blinks every 4 seconds                                                         | Sleep                                                        |
| Red, 1HZ rate, 50% duty cycle (Battery low condition: battery voltage 3.7V)           | Battery Low                                                  |
| Red, 4Hz rate, 50% duty cycle (Battery extremely low condition: battery voltage 3.6V) | Battery Extremely Low                                        |
| Orange, 1Hz rate, 50% duty cycle                                                      | Battery Charging                                             |
| Orange, continuously on                                                               | Charging Timer Fault                                         |
| Green, continuously on                                                                | Normal Operation                                             |
| Off                                                                                   | LEDs are turned OFF when charging the e355 on a gang charger |