[rescue] RE: Submarine batteries

[James Lockwood]

On Sun, 12 May 2002, Loomis, Rip wrote:

>  - 6 submarine-cell batteries will also (conveniently) produce
>    ~12V, which there are plenty of inverters to turn into
>    110VAC (okay, really more like 115-120VAC RMS, but who's
>    counting...)

Per NEC the voltage spec is 120V, half of the split-phase 240V.  Tolerance
is supposed to be 110V-125V.  "110V", "220V", and even "440V" are
mislabelings unless they apply to allowable voltage ranges.

Bucking 12VDC up is relatively inefficient.  Inverters designed for
serious use are usually designed around 24VDC at a minimum, and more
frequently 36-48VDC.

If the original poster isn't familiar with alt.energy.homepower, READ IT.
They've gone over off-grid living extensively and have built up a large
repository of experience.  Reliable continuous-duty inverters are harder
to find than you might think, Trace is the big name in the biz (the SW4024
is great if you need to run a well pump or the like).

Forklift batteries are a favorite over at a.e.homepower, esp the
12V/510A-H ones.

> So it looks as though 6 submarine cells might actually
> suffice for a backup to windmills...as long as local floor
> loading permits (7500-9000 lbs. for 6 cells depending on
> certain details...)

Standard residential floor loading is around 50psf (75psf for new
construction).  Sounds to me like pouring a slab is necessary here.

-James