tranny battery issue

[gainsy]

I am trying to charge my batteries in my etronix tranny via the charging plug but it keeps charging for about 30 seconds then reset's it's self, i am only charging at 1a & have tried taking the charge rate down to 0.2 but it keeps doing the same thing :confused:
The batteries are 2500mah rated
Any ideas guys?

[TheReferee]

ensure your charging jack is positive centre or negative centre, each manufacturer varies