Great deal on BatteryMinder maintainer - $24

rfuss928

Much higher current capabilities than most "maintainers" plus desulphation.  High quality construction.  $24



http://www.northerntool.com/shop/tools/product_200332201_200332201?utm_source=CSE&utm_medium=Shopping.com&utm_campaign=Automotive > Batteries, Chargers + Jump Starters&utm_content=167981

Tabaz

Had to buy one of these to plug my battery tender into the Zamp port on the tub:

https://www.amazon.com/gp/product/B00AHCWGOO/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

Not sure if this model would need one.

Nomad

Walmart also has reverse polarity SAE cables - In the fishing/marine section.