What is poe eldritch battery?

Poe Eldritch Battery is a passive skill in the action role-playing game Path of Exile. It converts all energy shield to mana and also grants players the ability to recover mana instead of recharge energy shield with energy shield recharge effects. Essentially, this passive skill allows players to use their energy shield to power their abilities and spells, rather than protecting themselves like traditional shields. It is a popular choice for spellcasters and builds that rely heavily on mana.