On Fri, 22 Mar 2013 16:57:55 -0000, "Keith W"
wrote:

GunnerAsch wrote:
On Fri, 22 Mar 2013 12:40:50 -0000, "Keith W"
wrote:

GunnerAsch wrote:
On Fri, 22 Mar 2013 09:23:17 -0000, "Keith W"
wrote:


The conventional Batteries are sometimes called Sealed Lead Acid
Batteries but they are actually AGM batteries.

Modern passenger aircraft normally use Nickel Cadmium batteries

Why havent they converted over to NmH?

They have a relatively high self discharge rate and can lose
up to 20% of the energy stored in the first 24 hours. This is
acceptable for hybrid vehicles where the battery is primarily a
temporary buffer to capture the energy from regenerative
braking but not good for a system intended to initiate an
aircraft startup sequence after a week in the hangar.

Keith

Thats not true anymore. Since Sanyo developed the Enerloop NiMH
battery..they are being shipped charged from the factories. All the
makers are using the new tech and have been doing so for at least 3
yrs. Ive got NiMH batteries that I only need to put on the charger
ever 6 months, just to top them off.

Gunner

Trouble is they are not available in the size or capacity to be used
in an electric vehicle, last time I checked the largest was a D size.

Keith

The Tesla Roadster has 6,831 lithium-ion cells, and each one is
between the size of a AA and a C in diameter, but a little longer than
either.

An AA is 14.5 mm x 50.5 mm. The 18650 Form Factor cells used in the
Tesla are 18.6 mm x 65.2 mm.

--
Ed Huntress