Power Cells

All portable energy sources come in the form of Power Cells. basically batteries.
Power Cells can be recharged at a recharging station. All energy stored comes from the power grid which converts ambient magical energy into a power source that can be stored and used.
Power Cells come in different sizes: AA, A, B, C, D, and E They start very tiny and get bigger and heavier and more expensive.
Here is the basic rundown of each power cell:
AA cell: This cell is a disk the size of a pinhead, 1/16” in diameter and 1/32” thick. AA cells are used to power microbots, brain implants, calculators, etc. They cost 2 Copper 500 AA cells weigh 1 ounce.
A cell: An A cell is a cylinder 1/4” in diameter and 1/8” tall. A cells are used to power wristcomps, short-range radios and other devices with small power requirements. An A cell costs 10 Copper 25 A cells weigh 1 ounce.
B cell: B cells are cylinders 1/2” in diameter and 1/2” tall. They are used to power various sorts of hand-held equipment, including small, easily-concealable weapons. B cells cost 30 Copper 20 weigh 1 pound.
C cell: This is a 1” diameter by 2” tall cylinder. C cells are the most common power source for personal weapons, tools and equipment. They are the most familiar power source in most advanced societies; equipment designed for larger or smaller cells often has an adapter for C-cell operation. C cells cost 100 Copper and weigh 1/2 pound.
D cell: A D cell is a cylinder 2” in diameter and 4” tall. D cells power military weapons and heavy equipment; TL8+ battlefields are littered with expended D cells in the way that TL7 battlefields are littered with expended cartridge cases and machine gun links. Each D cell costs 500 Copper and weighs 5 pounds.
E cell: Each E cell is a cylinder 4” in diameter and 6” tall. E cells power vehicles, support weapons and other power-intensive systems. An E cell costs 2,000 Copper and weighs 20 pounds.
Replacing Power Cells It takes 3 seconds to replace an A, B, C or D cell with a new one, or 6 seconds to replace a tiny AA or large E cell. Speed-Load (Power Cell) skill (see p. B52) applies to B, C and D cells being reloaded into weapons. Successful use of this skill reduces the time to 1 second.
Keep in mind some of the descriptions are not 100% accurate as this world isn't quite a full TL8, but it is enough to give you the basic idea.
Power Cells and Magic First, let me introduce you guys to Powerstones. Powerstones are enchanted gems that store fatigue. The fatigue can be drained from the stone to power spells (but not Psi). They recharge their power. They can be very useful as batteries. There are rules about how they are used and how they recharge, but not important for right now. Powerstones are magic items. They are one of the most basic items to enchant and the small ones are fairly easy to create (in the grand scheme of item creation).
Okay, now that we are aware of Powerstones, let's talk Power Cells. Power Cells can be used like a Powerstone. A caster (both mages and clerics) can draw the power out of a Power Cell to power a spell they are casting. Drawing the energy in such a fashion from a Power Cell destroys the cell. Even if the caster does not drain the cell, it is still destroyed and cannot be used for power again (mundane or magical), and it will never recharge. it is burnt out.
There are Technology spells that allow the caster to draw energy from Power Cells without burning them out. This method does not give the caster full access to all the energy in the cell, only a ratio of it, but the cell can recharge its power and be used again in such a way.
You can only draw energy from one power cell or powerstone at a time.
Power Cell Fatigue Levels AA cell = 0.01 Fatigue. A cell = 0.1 Fatigue. B cell = 1 Fatigue. C cell = 10 Fatigue. D cell = 100 Fatigue. E cell = 1,000 Fatigue
Vehicles and Power Cells Vehicles have their own power plants that run with specially made power cells that cannot be drawn from, unless you have Technology Magic This special design was an attempt to stop casters from constantly burning out people's cars.
It is possible to rig up a normal power cell to a vehicle power plant.
A vehicle's power plant continually charges the cell which in turn powers the vehicle.
If for some reason a vehicle's cell is drained, you need to replace it.