Sorry 4*60, you are wrong. I've worked with these batteries for many years and the 13.7 volts is the proper number. You might want to check with an expert, Red at Hangtime hobbies for further info.
www.hangtime.com/redsbatteryclinic/html or check with some of the ARRL info as HAMs used to use lots of these Pb cells and have published several articles on chargers for them and what voltage levels you can expect to see.