unless your charger states it can charge lead acid batteries...you cant......the 989 can...i dont think the 977 can tho...nor can the Ice....and on the 989 you set it to 2 cell's...not 6.....you prolly screwed that battery up already....and like ezeedub stated...once a gel drops below 12.6 its Fubar'd....it might come back to life...but its been hurt period.