We get the red Anderson connectors from our local Grainger warehouse.
www.grainger.com
To ensure a secure connection, we crimp and solder; because the lugs & wire are so large, we often have a mentor do this with a torch.
To connect to the battery, you want something similar to:
http://www.foxelectricsupply.com/con...ctNo=BTC020 8
They sell similar connectors at Home Depot.