[OT] More on Batteries

[Steven Elling]

On Tuesday 13 May 2003 12:16, Brian Densmore wrote:
> > Stored batteries will loose up to 10% of their charge per
> > day.  Obviously, any
>
> That would make a battery dead in 10 days. I find that hard
> to believe.

That would be 10% of the 'remaining charge'. i.e.

12V - (12V * 10%) = 10.8V
10.8V - (10.8V * 10%) = 9.72V
8.748V
7.8732V
7.0859V
6.3774V
5.7397V
5.1658V
4.6493V
4.1844V
3.7660V
3.3894V
3.0505V
2.7455V
2.4710V
2.2239V
2.0016V
1.8015V
1.6214V
1.4593V
1.3134V
1.1821V
1.0639V
.9576V

Which means the battery would be effectively dead after 24 days when it has 
less than 1V of charge.  Is that believable for some battery types? Maybe.

However, what about alkaline batteries?  I'm looking at some Rayovac's that 
have Dec 2009 written on them.  What about lead-acid batteries?  I've had 
lead-acid batteries in cars that sat for over 6 months and were still able 
to crank over the engine.