Sun 2500 Electronics Question

[willsun]

 Hello Jeanneau Owners,
I own a Sun 2500 but I think this may be a generic Jeanneau question. The attached photo shows the Nagres starter relay. To the right is an electronic component: what is it and what does it do?

Regards

Will

[allstar2500]

Hi, not sure of the technical terminology but I think that is the gubbins that manages the charging from the alternator.   Red light on means it's charging.   

[willsun]

Thanks allstar2500, although I did have to look up ‘gubbins’