The Legend of Zelda: Tears of the Kingdom features a new addition to your main indicators of health and stamina: Battery Energy. This comes in the form of an Energy Cell key item given to you early in the tutorial, and will track how much power you can extend to Zonai Devices when they are activated in your proximity. This page explains how your battery works, and how you can upgrade it by increasing its duration at a Crystal Refinery.

How the Energy Well Battery Works

The Energy Well (Which is displayed by a battery icon) has three cells of power that will deplete when certain devices are active, and will slowly replenish when the devices are turned off. Since the energy well takes up one of eight spaces on the Energy Cell visible on your hip, you’ll be able to constantly upgrade your maximum power over the course of the game. The process for this can be a lot to take in, but once you know how and where, upgrading the remaining parts of your Energy Cell will get much easier.

Note that unlike health or stamina, you can not only replenish lost energy by using a Zonai Charge dropped from Warrior Constructs, but you can also temporarily extend your maximum battery power by continuing to use Zonai Charges. The extra battery will appear in yellow, similar to extending maximum health or stamina by eating certain meals or sleeping in special beds.

Getting Crystalized Charges

As you explore the Great Sky Island near the start of the game, you’ll pass through a darkened Mining Cave where a Forge can be found on the south side of the island. The Forge Construct here will inform you that he can process Zonaite into either Zonai Charges, or Crystalized Charges. While the former can be used as a temporary energy extension, Crystalized Charges are needed to permanently extend your Energy Cell Battery.

You can browse his shop to find that the Zonaite you carry (mined primarily in The Depths, but also found in certain caves and Sky Islands), can be traded in, with 1 Crystallized Charge worth 3 pieces of Zonaite. However, the Forge Construct will only have a limited supply at one time, and like other merchants, you’ll need to visit him again later when he restocks. You can usually get 10 Crystallized Charges in total per visit if he’s fully restocked.

Luckily, the Forge is not the only place you can find Crystallized Charges, as they can also be found by defeating certain tough enemies in The Depths, as quest rewards, or by finding secret chests while exploring the darkened underground region. These forges usually have a much bigger stock, and allow you to turn in Large Zonaite for Large Crystallized Charges worth 20 regular Crystallized Charges.

Later on after you have completed at least one of the Regional Phenomena, Josha and Robbie will task you with searching the Depths for a special area, and concluding the quest will reveal another Forge area in the Depths to trade at.

If you continue the Side Quest that expands from this, it will take you to several other important locations in The Depths, and each will reveal a new Forge location to buy more Crystallized Charges.

How to Use the Crystal Refinery

Next to the final fourth shrine in the Great Sky Island, the Nachoyah Shrine, you can find a different Steward Construct by a tall pillar. The place is a crystal refinery, and uses 100 Crystallized Charges to increase the Energy Well of your battery, which adds 1 of the 3 bars that makes up the battery icon.

Given that the Energy Cell on your hip has 8 slots for full batteries that have 3 energy wells each (including the one you have from the start), it means you can get a total of 21 Energy Well upgrades for 8 full batteries. However, this also means you’ll need to find or trade for 2,100 Crystallized Charges to fully max out your device.

Consider always making time to mine Zonaite and visit forges as you unlock them when exploring the Depths, and return to the one on the Great Sky Island to check for replenished stock.

Aside from the Crystal Refinery on the Great Sky Island, a chunk of rock has also fallen just outside Lookout Landing with the same tall pillar you can inspect to find another refinery location that’s much easier to get to.

Expanding your Energy Cell isn’t exactly required to progress in the story, as you can always use large quantities of Zonaite Charges to keep your battery powered when needed, but having a permanent upgrade will allow you to save on those resources for when you truly need them.