Plug it in, change the world
Energy Cells are something of a new concept in The Legend of Zelda: Tears of the Kingdom. Whenever you use a Zonai contraption, it immediately starts draining from your energy cells. That’s the little battery icon.
Tears of the Kingdom does a great job of indicating that these energy cells can be increased by physically showing blank sockets on Link’s belt, but it mostly leaves out how to fill these. I’ll be upfront; it’s a long road to getting more energy cells. You’ll need to trade Crystalized Charges. There are a few ways to find Crystalized Charges, but the most expedient way is trading Zonaite to Forge Constructs. Here we’ll show you how to go about doing that.
The Foundry
The first Forge Construct you meet is up in the tutorial area of Great Sky Island. However, that guy sucks. He never has very many Crystallized Charges to trade for Zonaite, so while he’s in a convenient location, actually getting what you need can take a great deal of time.
Thankfully, he’s not the only Forge Construct, and the others that you find tend to have more stock. The bad news is that the other Forge Constructs are in the depths. The good news is they’re mostly in obvious spots. The worse news is that just because they’re obvious spots doesn’t mean they’re easy to get to.
For example, one Forge Construct is directly below Hateno Village. The closest chasm, on the other hand, is quite a ways due North of Hateno. There’s a Lightroot nearby that you can later quick travel to, but that’s not going to help you get there to start.
Similarly, the other Forge Constructs seem to be located beneath overworld settlements.
Exchange rates
Once you reach a Forge Construct, you’ll be able to trade for larger quantities of Crystallized Charges. Now for some more bad news: the exchange rate is horrible. You need 3 regular Zonaite to buy one Crystallized Charge. If you have 3 Large Zonaite, you can buy a larger one that is worth 20 Crystallized Charges.
Once you buy out a Forge Construct’s stock, you’ll have to wait for them to restock. You can do that if you’ve got the patience, but you might be better off finding another Forge Construct or getting Crystallized Charges through other means.