OK, um, I just feel compelled to say that some women do batter. It's not unheard of. Both in male/female and lesbian relationships, and with all of the same psychological puzzles, shackles, and troubles. Plus some. Especially because society at large is unlikely to take this situation seriously, there are few legal or social resources available to a battered man (or a battered lesbian, depending on the community).
Just like battered women, battered men may feel trapped in the relationship, blame themselves, and be embarrassed to admit that it's happening and that they haven't helped themselves yet. A women's shelter or other related organization may be able to help him find his way out of the situation.
People think men and women are so different. Sheesh. The main difference is the different sets of assumptions, constrictions, inhibitions, and prejudices heaped on them by the society they grew up in.