Ok my wonderful girlfriend has bought me a new boat for the fleet.
Its got no history with it but its in immaculate condition and ready to run bar the battery. The only info I've got is it was run on a 6v battery and it has one of these connectors:

The gap looks like it was made for a SLA battery BUT it is pretty small (13cm x 50cm and 80cm high) so the only battery Maplins sell that will fit is the 6v 1.3Ah one and that seems to be a bit of a low Ah rating. (I know nothing of how this affects the operation, I'm a thicko when it comes to batteries)
Is that going to do the job? Its a twin screw, running on 2 x 400 motors from the look of it and a pretty big rudder
What do the electrickery experts out there think I should be running this beauty on.
Any and all help VERY appreciated.
Alex