I think the majority of the people that have posted a reply do not understand the question. He knows he needs a tender, but he has no AC source to connect the tender to.
The only thing I can recommend is to use a standard powerpack to supply the tender.
You'll have to recharge the powerpack periodically, but you can work out a schedule for that.
http://www.canadiantire.ca/AST/brows....jsp?locale=en