Defender 90 battery light won't go off

Basically I went away holiday for 10 days my farther disconnected my battery and put away in the garage to stop it being stolen so came back connected it all back up checked if it was fully charged and it needed abit it charging so charged it up then stuck it back in the defender and now have the red battery light on. Which doesn't go off :/ so went for a half an hour drive to see if that would help and hasn't. Not sure what's up but the truck starts fine nothing different to before it was disconnected if anyone could give me some advise that would be great

Many thanks Barry90

Have you checked the battery voltage with it running? Should get 13.5 to 14 volts if it is charging, 12.7 or less means not charging. If not charging then you need to be looking at alternator.

I will do that thanks

you didn't mix the battery leads up for a split second did you?