Battery problem with mk6 tipper...HELP!

[Alynjones9]

Hi,
I have an issue with my 2002 mk6 tipper 2.4 RWD.

I went out to the van this morning and went to start it and all it was doing was clicking as if the engine was was trying to start, I opened up the bonnet and had the mrs turn the key whist i looked in the engine and as it clicks the engine move slightly as if it is trying to start (i was thinking low battery)
Anyway i removed the black wire from the battery for 1 min and then reconnected it and and turned the key and the van fired up first time but the battery light remains on.

Any suggestion what it could be or what to test.

any help is really appreciated.