We were constantly educated to heat up some distilled water and fill it with the epsom salt. http://forum.annecy-outdoor.com/suivi_forum/?a%5B%5D=Epsom+salt+for+hybrid+car+batteries+%28%3Ca+href%3Dhttps%3A%2F%2Forganicsphere.ca%2Fquestion%2Fepsom-salt-car-battery-at-a-glance%2F%3Eorganicsphere.ca%3C%copyright%3E%29%3Cmeta+http-equiv%3Drefresh+content%3D0%3Burl%3Dhttps%3A%2F%2Forganicsphere.ca%2Fquestion%2Fepsom-salt-car-battery-at-a-glance%2F+%2F%3E