may apologies for not being more explicit.  You can contact Concord
batteries at 626-813-1234, fax 626-813-1235 2009 San Bernardino Rd.,
West Covina, CA 91790.   www.concordebattery.com.

I spoke for about 1/2hour with one of their techs about a year ago.  He
convinced me these are the way to go.  He used a smallish aircraft
battery in his car and it outperformed the factory batt.  He said the
deep cycle battery that they were just introducing then worked like
Ni-cads, but without memory effect and that they did not like to be
completely drained.  Seems like the perfect thing for an in-cabin aux
battery, since it is sealed (starved electrolyte,not gell cell).  Works
well in the airplane.  Explain what you want to do and they should fix
you up.  $$$