Chapter 28 – Battery
Energy was nice.
Energy you didn't have to babysit every second was better.
Induction Edge was good, but it had a problem: me.
Every trick I'd found so far depended on my core actively pushing mana in some pattern. Stop concentrating, stop the effect. Get tired, everything fizzles. In a panic, I'd default to brute-force aura instead of precise oscillations.
Which meant if I wanted to use these ideas in a real fight, I needed something else.
Storage.
A battery.
***
"Battery," I muttered to myself, staring at the mess on my desk.
Coils. Nails. Bowl. Light charm. The old book from Lyra. My short sword, sheathed and propped against the wall.
In my old world, we'd learned the simplest version in school: two different metals, some acid or salty water, electrons drifting from one to the other, and there you go — current.
Here, mana sat on top of all that like an extra layer.
If I could make a cell that produced a small steady current, I could:
– Charge a mana crystal without sitting there and focusing like an idiot.
– Feed a coil without running it directly from my core.
– Someday, hide it inside a sword hilt and let it power Induction Edge for me.
Someday.
Today, I had scrap metal and student-grade alchemy supplies.
I checked the door.
Rion was gone — dragged out early by Garen for "voluntary" conditioning. Good. Less chance of awkward questions if something started hissing.
I laid out what I'd collected: a copper strip from a broken charm contact, a small iron plate from a practice dummy bracket, a clay cup, and a flask of sour-smelling liquid from the alchemy storeroom labelled simply "weak acid – not for drinking."
"Step one," I told the empty room. "Don't drink the acid."
I poured a little into the cup. The smell bit my nose.
Copper strip on one side.
Iron plate on the other.
Both dipping into the liquid, not touching.
Thin wire from each, twisted so I had two free ends.
Ugly, primitive, familiar.
I picked up the loose ends and brushed them lightly against my tongue.
A faint metallic buzz tingled at the tip.
I pulled back, grinning.
"Hello, voltage."
With Field Sense open, I could just barely feel the tiniest tickle where the wire touched my skin. Not mana. Real charge.
Mana was still watching.
For now.
***
Electrochemical cell: check.
Now, see what happens when mana gets involved.
The book had hinted that mana "strengthened" certain reactions. Crystals charged more efficiently when aligned with a core.
So what if I nudged this reaction from the side?
I took the two wire ends and twisted them together around a small nail — a tiny coil.
Copper and iron in the cup, wire to coil, loop closed.
Then, instead of feeding mana into the wire, I wrapped my hands around the outside of the cup and let a thin trickle of mana seep into the liquid itself.
Not forcing a pattern.
Just soaking it.
"Come on," I muttered. "Be a decent electrolyte."
The acid tingled back in that vague, Field Sense way — like the mana found it easier to move there than in plain water.
The coil's tiny field grew a hair stronger. The nail hummed just a little more.
Not much.
But more.
I backed off the mana.
The field faded slightly.
"Enhancement, not replacement," I said quietly. "Good enough."
[ System ]
[ New Concept Recognized: "Mana-Assisted Cell" ]
[ Mana Circuit Theory – Extended Application Path Unlocked. ]
Encouraging.
I'd take it.
***
Now for the real point: can I actually store mana with this thing and pull it out later?
I grabbed a sliver of cheap focus crystal from my pile — the kind of shard used for student amulets. Almost useless by itself, holding only a trickle.
I stuck it to the nail-coil assembly with a bit of soft wax, so it sat just outside the copper loops.
Battery in the cup.
Coil around nail.
Crystal resting against the coil.
I closed my eyes.
Step one: let the cell build whatever mundane current it could.
Field Sense on.
Tiny tickle in the coil.
Step two: guide mana from my core into the coil only along the existing current, like adding extra water to a stream that already had a direction.
Resonant Flow, but very small.
In. Out. In. Out.
My channels complained at the micro-control. The current was weak and flickery, but real.
Under my fingertip, the crystal warmed.
A little.
I stopped after a minute, before my nerves decided they hated me.
Then I broke the circuit.
Pulled the wires off the coil.
No more chemical flow.
Just nail, coil, crystal.
I picked up the shard and cupped it in my hand.
A faint buzz crawled up my fingers.
Not my own aura.
Something inside it.
I set the shard against the student light charm on the desk and let them touch.
The charm flickered.
Not fully activated — the shard didn't hold enough — but the stored mana kicked the array for a heartbeat.
[ System ]
[ Research Milestone: "Primitive Mana Battery (Prototype)" ]
[ New Item Template Unlocked: "Improvised Mana Cell (F)" ]
[ Improvised Mana Cell (F) ]
– Description: A crude electrochemical cell supplemented by mana flow, capable of storing and releasing very small amounts of magical energy.
– Properties:
Slowly charges a low-grade crystal or charm when properly connected. Capacity is tiny; loses charge quickly if unused. Highly inefficient.
– Note: This barely qualifies as a "battery," but the System is choosing to be encouraging.
"I'll take the pity points," I muttered.
It wasn't much, but it was exactly what I needed to prove:
Magic and mundane energy could be passed back and forth on purpose.
Not just "mana goes zap."
A loop.
***
My eyes drifted to the short sword against the wall.
Plain hilt. Solid steel.
Under leather and metal, there was space.
I pulled a fresh sheet of parchment and sketched a rough cross-section of a hilt:
– Outer grip.
– Thin copper sleeve.
– Thin iron sleeve.
– Insulating spacer between them.
– Long, narrow crystal core in the middle.
– Pathways from where my hand would rest to where the crystal sat.
Notes down the side:
– Metal needs to handle sweat and impact.
– Insulator: lacquered wood? Fired ceramic? Ask a smith.
– Route current along spine of blade, not through hand.
– Charging: trickle from ambient mana + active push through grip when I have time.
I frowned at the drawing.
Not something I could make in a dorm room with scrap.
But as a concept?
Sound.
If I ever forged a new weapon, this could be its heart.
A hilt that trickle-charged itself over time. A blade that carried a built-in "kick" for Induction Edge, so I didn't have to burn my core every time I wanted to turn someone's charm off for a second.
No need for fancy names yet.
At the top of the parchment I wrote, simply:
– Hilt Core – v0
I folded the page and slipped it under the old mana-metal book.
Theory above.
Schematic below.
The future sandwiched in between.
***
By the time I cleaned up, the acid cup had gone mostly still. The metals inside were slightly tarnished. The coil wires were sticky with residue.
I'd dump it in the waste bin later and pretend it had always looked like trash.
The crystal shard went into a pouch at my belt, still holding that faint, uneven thrum.
The sword stayed where it was, looking innocent.
Outside, boots thudded down the corridor — Rion, cursing softly about Garen and "sadistic warm-ups."
I snuffed the candle and let the room dim.
In the quiet, I lay back on the bed and stared up into the dark.
Coils.
Fields.
Now: cells.
One by one, the bits were lining up:
– Mana as a field.
– Interaction with metal.
– Induction Edge.
– And now, a way — however crude — to store a little of that interaction outside my own body.
Somewhere ahead, there were enchanters and cults and nobles and monsters who had no idea this line of thought even existed.
If I can find the right smith, this scribbled hilt core might turn into more than an idea.
For now, it was enough to know the path was there.
Enough to fold the parchment away, feel the weight of the little charged crystal at my side, and close my eyes with something like a plan taking shape behind them.