I dont mind using the sealed lead
acid batteries but the NIMH has many advantages . And yea, I know
price isnt one of them.
Thanks

NIMH?!? If cost doesn't frighten you, then why not LiFePO4?
http://www.valence.com/products/batt...es/u-charge_xp
http://www.valence.com/sites/all/the...ta%20Sheet.pdf
http://www.valence.com/products/batt...es/u-charge_rt
(integrated battery maintenance version...)
http://www.valence.com/sites/all/the...ta%20Sheet.pdf
Kick a$$ batteries with 1/4-20 threaded connections to boot...but
certainly not cheap. Just talked to a nice lady there at Valence, and
for reference:

40 amp/hr is $800 (U1-12XP, their battery which is the same size as a
12v 12 amp/hr lead brick but half the weight)
24 amp/hr is $600 ( U1-12RTL, same size/weight as above but with
built in battery management system)
Both series are claimed to be able to be charged on most standard lead
acid chargers (set for AGM/GEL cells)

-Paul