Please note, that iSocket only needs a battery for the purpose of informing you about a power outage in your electric network (AC network). If power has failed, you do not have electricity in your house and therefore you cannot do anything with electric appliances. So there is no reason for iSocket to continue to work from the battery. As soon as iSocket has sent a message about a power loss, it goes to shut-down. After the power is restored it will send a power restore message. All iSockets that support the iSocket Power Notifier feature have a top quality re-chargeable li-ion battery that is sufficient to power a module and send a power interruption alert to your cell phone even if there was a break in the network. iSocket will wait for a signal and will then send a message. We do not use super-capacitors as the cheap products of our competitors do, because super-capacitors may not provide enough power and manage a situation when the mobile network has been lost. We invented this technology and we know better how to use it. We use only high quality batteries and that is why our power outage alert feature is reliable. Watch video on our YouTube channel about power failure features of iSocket.