Yesterday afternoon the Guilford Fire Department responded to a residence to check a phone charger that had caught fire and exploded. The owner of the portable battery charger stated that the portable charger was charged approximately 2 hours before the charger caught fire and exploded. The charger was not plugged into an electrical outlet and was lying on a desktop at the time of the fire. Please use caution if you have these types of portable chargers that contain lithium-ion batteries. Do not leave them on any combustible items such as beds and couches and do not leave them unattended while you are recharging the battery pack.