Currently E-series systems used "Smart Batteries". This is a type of battery based on newer technologies that utilize different chemical compounds and provide complex support circuitry to provide estimated usage times. This type of battery can typically be exposed to a controlled discharge and recharge (learn cycle) which will restore the power capacity and extend the useful life of the battery. This type of battery can be used as long as it can be charged to a level sufficient to protect cache memory for a minimum required duration.
If the Learn cycle finds issues during the process of discharge/charge of the battery, the system will trigger an "insufficient learned battery capacity" alert and in the Major-Event.log an "Incomplete battery learn cycle" message will be displayed