The heart of crafting advanced batteries lies at caravan island during chapter 3, where you'll discover the blueprint (it's fascinating how these advanced technologies were left behind by previous survivors). Once you've got your hands on it, bring it over to the research table - this unlocks the real potential of sustainable power on your raft.

The crafting process requires 2 copper ingots, 2 scrap, and 4 titanium, which might seem like a lot at first, but it's worth it because these batteries pack 3.5 times the capacity of regular ones (making them especially valuable during long voyages between islands). You can power all sorts of essential equipment like water purifiers, electric grills, and receivers - this broader compatibility exists since the advanced circuitry allows for more stable power distribution.

What makes these truly game-changing is their ability to be recharged using the battery charger (and even the wind turbine), which means you're not constantly hunting for materials to craft new ones (try keeping a spare charged battery around for emergencies). This renewable aspect fundamentally changes how you manage power on your raft, making your operation much more sustainable in the long run.