Scott, "I replaced four Lifeline 8D AGM batteries with 12 Discover L-16 6-volt AGMs" Very interesting package alternative! Is it industry standard, or unique to this manufacturer? How about dealers, pricing, availability? No price/dealer info found on manufacturer's website. Did find a solar website that wanted $725 per battery. Not so interesting (to me) at that price! Thanks Peg and Jim Healy aboard Sanctuary, currently at Rock Creek, Pasadena, MD AGLCA # 3767 MTOA # 3436