"Rick M" wrote:

"Roy Smith" wrote

On the wet side of the house, the modern lead-acid cell isn't much
different from a lead-acid cell from the Civil War era. The glass tank
gave way to bakelite and then to plastic, and we've got gel cells now, but
all those are minor details.


Let's see ... just since the 1970s we have gone from batteries that lasted
at best three years to batteries that routinely have a five-year warranty.
Further, I'd achieved 9+ years on a battery in my small truck

That's a 2-3x improvement.

Again, NiCd cell capacity has quadrupled in the last 30 years

OK, a 4x improvement.

2, 3, 4x over the span of 30 years is certainly an improvement, but I'm
comparing it to digital electronics, where improvements over a similar time
span are more like 1000's fold.

I'm typing this on a 2-year old laptop. 3/4 of a gig ram, 40 gig hard
drive, 1 GHz processor, 1024 x 768 x 24-bit color display, wireless
ethernet, DVD-reader (CD-burner). It cost me about $1800 and weighs under
5 lbs. 30 years ago, some of those specs could be met for millions of
dollars, some couldn't be met for any money. The machine that could come
closest would fill a room bigger than my house and I couldn't afford the
electric bill to keep the lights blinking.

But, you know what sucks about my laptop? The battery. It's probably 25%
of the weight of the machine, and can't keep it running more than about a
half hour any more.