>Date: Thu, 19 Mar 92 9:43:02 MET
>From: [email removed]
>Subject: (3861) Batteries of Batteries
>
> Well, here is what 3G^3 has to say about batteries at our TL (8). One Watt is
>one Joule per second, so 1 Wh is 3.6 kJ and 1 MWh is 3.6 GJ.
[material deleted]
So lead-acid gives us 1 MJ for 8.6kg, and NiCad needs only 3.3kg, roughly.
I calculated that the current sodium-sulfur (NaS) battery gives 1 MJ for
2.2 kg and the metal alloy hydride needs around 1.7 kg. These numbers are
rough since the given stats were not precise.
> So you see that to get 1MWh, rechargable, we'd need 30 tons of car batteries
>(the volume would probably be quite small, though) and I think that this is
>the kind of batteries that subs use.
Assuming it is merely 12-volt lead-acid scaled, I get closer to 31 T.
> I guess that the figures for all the new funny batteries (Sulfur-?) are much
>better than those above.
The NaS 1MWh weighs around 7.8 T, and metal hydride of the same capacity
weighs a mere 6.1 T. These new batteries have energy densities about 4 and 5
times that of lead-acid respectively. Where does that put us on the NASA
projected tech chart?