Well I tried the Interstate Battry Site.....Still no mention of specific gravity nor of equalization. Frankly the site is amateurish. The Exide Battery site as well gave no mention of equalization, but did say a fully charged 12volt batt is 12.6 volts and 1265 specific gravity but was unclear at what temperature. At least the T 105 site referenced by Ed gave a criteria...to equalize when fully a fully charged specific gravity varies by =/1 .15 from cell to cell...at least there's a criteria. This is the same lack of information I discovered about seven or eight years ago. I'll find it interesting when I get back to my boat to check and compare specific gravity from cell to cell and see if I can detect any variation. I hope Interstate makes batteries better than they describe them. Rob 1972 Hatteras YF New Rochelle, NY _________________________________________________________________ Test your Star IQ http://club.live.com/red_carpet_reveal.aspx?icid=redcarpet_HMTAGMAR