Spaceships series: Electrical Batteries module?

[vierasmarius]

I've considered it before. For designs that are intended to use batteries, I've usually substituted in Fuel Cells and called it close enough. However, batteries would have the advantage of being chargeable, and potentially being able to provide quite a high output for a short time. Unfortunately, the Spaceship system modules are, shall we say, "opaque". I wouldn't even know where to start in making a realistic battery module.

EDIT: Well, I suppose we could start at the Chemical Energy Power Plants (Fuel Cell and MHD from SS1, Internal Combustion and Gas Turbine from Pyramid 3/34). Since they're all available at TL9 we'll compare them there, using a SM+7 module as the basis. Each module is 15 tons.

Fuel Cell: 11.25 tons, provides 1 PP for 12 hours per 3.75 tons fuel (48 hours per fuel tank)
MHD: 11.25 tons, provides 2 PP for 6 hours per 3.75 tons fuel (24 hours per fuel tank)
ICE: 12.5 tons, provides 1 PP for 10 hours per 2.5 tons fuel (60 hours per fuel tank)
Gas Turbine: 12.5 tons, provides 2 PP for 4 hours per 2.5 tons fuel (24 hours per fuel tank)

Surprisingly, the TL8 ICE comes out on top, with an "energy density" of 60 PPh (Power Point Hours) per fuel tank. The others are all at 48 PPh. A quick Wikipedia search puts the energy density of Gasoline at 47 MJ/kg, and the best batteries almost two orders of magnitude less (0.3-0.7). In other words, a realistic battery module would provide about 0.5 PPh capacity, or 30 PPm. This is probably why realistic batteries are not included among the ship systems. =P

For a cinematic battery, I could see it providing, say, 6 PPh per module, or 30 PPh for a blatanly Superscience version. Its advantage is that it could provide that all at once if needed (eg 6 PP for 1 hour) and be recharged afterward.