Wiring battery bank in series/parallel | DIY Solar Power Forum
You have two sets of 3 in series for 36V with those two strings in parallel. To make a 48V battery from 12V batteries you MUST have four 12V batteries of equal capacity. You have six. These are just evident truths you must accept... 12+12+12+12 = 48, the sun rises in the East and sets in the West, and a woman that says, "I''m fine" isn''t.