Have you looked at the S-cort from Vacsax. One of the benefits is that it will take a liner system and the charger is integral, not a seperate box to get lost.
It is manufactured by SSCOR.inc
http://www.sscor.com/pages04/moreduet.htm Seem to be liked here for units that get used infrequently and left on charge most of the time.
Brian
