Following our victory at Loja, the Emirate of Granada earned a vital breathing room. King Ferdinand’s forces retreated to regroup, terrified of our "fire-breathing iron monsters." But I knew Spain wouldn't stay quiet forever. To secure our future before the portal opened again in 1540, we had to modernize the entire military from a small royal vanguard into an industrialized, unstoppable force.
The key to this next phase wasn't more steam engines, it was electricity at scale. For that, I introduced the Lead-Acid Battery.
Its now the time for the lead-chamber process (1487-1488).
While our Gravity Cells were perfect for the low-current requirements of the telegraph lines, they couldn't be recharged efficiently and lacked the amperage to drive vehicles. Lead-acid batteries offered a massive evolutionary leap: they could dump massive surges of current to turn heavy motors, and they could be recharged by running current backward from our river-wheel dynamos.
Fortunately, 1487 Granada was perfectly positioned for this chemical revolution.
The lead bottleneck, unlike zinc, lead was incredibly abundant and cheap. Medieval smiths had been casting lead shot, roofing sheets, and pipes for centuries. Its low melting point meant we could easily mold hundreds of grid plates per day.
The acid revolution, the real challenge was mass-producing the electrolyte: sulfuric acid. To scale past the alchemists heating small clay jars of green vitriol, we already have the schematics for the Lead-Chamber Process (historically invented in 1746) by the scribes.
We built large, airtight chambers lined entirely with thick sheets of chemical-resistant lead. By burning sulfur and saltpeter (potassium nitrate) and introducing steam, the gases reacted inside the chambers to condense into high-purity sulfuric acid at an industrial volume.
Our alchemists transitioned into industrial chemical engineers. By mid-1488, we were casting lead plates, coating them in a paste of lead oxide (made by roasting lead in the open air), and submerging them in wood-framed, resin-sealed battery boxes filled with our new acid. We began building large battery-charging banks at our river-wheel power hubs.
I’ve also been able to create a socket that my charger could plug in to recharge my devices. It’s been almost a decade and every charge cycles count. The scribes already copied hundreds of schematics, manuals, guides at this point. My MacBook is reserved to only be turned on in an emergency.
Then we proceed with the electrifying logistics and perfecting the musket (1488-1489)
With a rechargeable, high-current power source unlocked, the House of Wisdom split into two main military modernization projects.
The Electric Logistics Wagon, while our three steam-powered *Al-Burraq* tanks were absolute battlefield monsters, they were loud, heavy, and fuel-hungry. For general army logistics, like transporting grain, black powder, and troops across the Sierra Nevada, I designed a fleet of Electric Supply Wagons, including the Emir’s personal car that looks like a car made in 1920s.
These vehicles utilized our standard Axial Flux Alternator run in reverse as a high-torque DC motor, connected to a heavy lead-acid battery bank in the wagon's belly.
They were completely silent, required no coal or wood, and could travel 15 to 20 miles on a single charge. At every outpost, fresh battery banks charged by local windmills or waterwheels were swapped in minutes, creating a rapid, horse-free supply chain.
The Personalized Hand Cannon (The Granadan Musket), the infantry needed an upgrade from crude, dangerous medieval handgonnes. Using the the mechanical manuals transcribed by our scribes, our metallurgists moved away from cast bronze to bored, high-carbon steel barrels.
We developed a standardized Matchlock Musket, later upgraded to a Flintlock mechanism using local flint deposits.
Most importantly, we implemented rifling; cutting spiral grooves inside the barrels to spin the bullets. Combined with our consistently granulated, corned black powder, ordinary Granadan foot soldiers could accurately drop a Castilian knight from 200 yards away, completely rendering plate armor obsolete.
Moving on to conquering the vacuum, light bulbs and relays (1489-1491), as our industrial base matured, we pushed toward the upper echelons of the community rebuilding prepper library, thats already been transcribed or codified into a book. Conquering the vacuum.
To expand our telegraph network across the entire realm, the signal degraded over long distances of iron wire. We needed electrical switches that could automatically amplify the signal.
We successfully built mechanical relays; simple electromagnetic switches where a weak incoming current from a distant city energized a small coil, pulling down a lever that connected a fresh, local lead-acid battery to push the signal along to the next province. This completely automated the network.
With automated relays functioning, I tasked Tariq ibn Sami with tackling the incandescent light bulb.
We couldn't build advanced mercury pumps yet, so we iterated on precision mechanical piston-based air pumps. Using oil-sealed leather valves and finely bored bronze cylinders, we managed to pull a crude but effective vacuum inside hand-blown glass bulbs.
Following the Edison method, we carbonized local bamboo slivers and linen threads inside sealed clay crucibles heated in our blast furnaces.
By late 1490, the command bunkers beneath the Alhambra and the primary watchtowers along the frontier were no longer lit by smoky oil lamps or flickering torches. They were illuminated by the steady, surreal glow of incandescent electric light bulbs, powered by basement banks of lead-acid batteries.
More power station is also developed too. The entire realm of the Emirate is lit by electric light bulbs and wind and waterwheel turbines. Someone in the order proposed to build a larger powerplant that could probably power the entire Iberia, scaled up steam power plants, the Emir refused. He doesn’t want his land to be filled with smokes, breathing coal ashes and turned the terrain ugly as he saw previously in my modern world depiction on my MacBook.