Hm. Okay, so this probably holds somewhat true for the minatoseal chakra batteries we plan on making. If nothing else, it gives us a starting point to plan from.
So, let's talk delineated boundaries, since that is going to be most useful for storage, as per Word of Kagome.
- Personal chakra, instead of environmental. We graft a chakra battery onto ourselves, and it stores our personal chakra that we direct into it. It doesn't seek out to drain environmental chakra that might turn us into stone (or turn around and drain our chakra from us) instead. Each battery seal would need to researched to synergize/resonate with the recipient, but I feel like veterancy would pile up quickly and make that less of a problem over time.
- Since we're limiting this to our own personal chakra signatures (the strength of which might be determined by our normal chakra capacity), it feels like such a chakra battery would be limited in capacity to the amount the recipient has at time of researching the seal.
- This will also help our chakra coils tank the injection/infusion of stored chakra. The greater the amount of stored chakra, the greater the force of the infusion hitting your chakra coils (would limiting the output of each infusion mitigate that?).
- If this is true, then you wouldn't want the chakra battery to be larger than your natural chakra coils... otherwise, you're coils could be hurt during the infusion process, itself.
- This isn't too bad, since it still ~doubles our chakra capacity. We should probably assume that the effectiveness is going to be more akin to 3/4ths or 2/3rds our capacity, though. Plan for unforeseen complications, you know?
- Containment. I feel like riffing off of Tailed Beast Seals would work, here. We would be placing the seal onto ourselves. Tailed Beast Seals can be placed on a living person just fine, so I don't see why this wouldn't also work. We're basically making an offbrand version of the Tailed Beast Seal, anyway. We're not even trying to seal away a fragment of the Tenfold Beast, we're just trying to seal our own chakra... should be far more doable, imo.
- This would allow us to transfer our internal reserves to the battery during rest days, and build up a nice reserve.
- It would also help take the chakra cost of FOOM down for Noburi.
- Triggers. We know that chakra manipulations are a thing, and that handseals are mnemonics that help guide that. We could create handseals to trigger the storage of chakra into the chakra battery, and a different pair of handseals to trigger the release? Charging the battery wouldn't matter (handseals could be as complicated/long as you like), but maybe we should shoot for "supplemental action" speed for the "access chakra battery" portion? Sure, getting a free action or reflexive would be nice, but... not, perhaps, realistic.