When a device is charging, the battery is receiving power from the cable, which can cause the device to warm up. Additionally, if you are actively using the phone while it is in a charging cycle, the constant draining and recharging of the battery can cause it to warm up quicker. However, if the device is hot to the touch while charging, please do unplug it and contact us directly at 1-833-MY-SONIM (1-833-697-6646)

If you need any further assistance with this question, please contact the Sonim Customer Experience Center at 1-833-MY-SONIM (1-833-697-6646) or email us at [email protected]  We are open 24 hours a day, Monday-Friday and we will further assist in troubleshooting.