That post cant have been a master post. I'm currently helping out a little with a local master post which has been renovated and the charging lead from the swan generator plugs into a socket behind the black cap on the air shaft. It also contains an rf connector and a pneumatic connector for the antenna mast.
The power from the generator then goes to a two way switch (on the far wall) which allows you to have one battery in use whilst the other one charges.
