Right now all batteries have "negligible" mass, but I was thinking that it would be interesting if batteries had varying masses. If light and medium batteries actually were lighter than heavy and fast charge batteries, it might make them useful. Something along the lines of:

Free Battery: 300 kg
Light Battery: 400 kg
Medium Battery: 800 kg
Heavy Battery: 1200 kg
Fast Charge Battery: 1100 kg

NOOOOOOOOOOOOOOOOOOO [Edited to be shorter]

ok maybe but take the mass down by like 1/5th.

i think the fast charge should weigh about as much as the medium battary. After all it is pretty small, it just charges fast.

But i'm shore somone will complaine about that being unbalanced.

Here's my take on the weights:

Free Battery: 200 kg
Light Battery: 150 kg
Medium Battery: 400 kg
Heavy Battery: 600 kg
Fast Charge Battery: 800 kg

Charging circuitry is heavy, people. :)

But energy storage is terribly inefficient and bulky.

-Something- needs to be done about batteries. The light and medium batteries serve no game function except to keep new pilots out of PvP, which goes against the spirit of the game.

I like Spellcast's battery idea best. Charging rates should be a property of the ship, and batteries should have capacity only. Then follow the OP's suggestion -- the more capacity you want, the more mass it takes. Big ships should be able to take gigantic batteries without much of a problem (here comes an all-energy Ragnarok) but small ships would have to keep an eye on flight performance vs. battery capacity.