Gilera DNA 50 (2006 RST Model) Electrical Issue

I haven't used it for about 6 months, so the battery is dead and it took about 200 kicks of the kickstarter to get it running.
Everything worked fine and hasn't been out of the cover since then.

Working:
Headlights/highbeam switch, and the LED indicator for those
The dash is backlit
Tail lights

Not working:
Horn
Nothing on the dash display, just the LED backlight
Indicators
Brake lights
Electrical starter switch

I'm hoping the battery just needs charging and then it will all work again, but if the headlights are working I don't see why there's not enough juice to show anything on the dash display?

Could it be the fuse? I've got spares, will try a new one tomorrow.

I don't have a charger, but how long would it take to charge enough to get the other things working if I left it running on the stand? (assuming it is the battery)

Pretty sure it's probably the battery but just wanted to get any thoughts before leaving it running to charge tomorrow.

Thanks in advance.

 

Dry stored or outside under a cover?

 

Outside under cover.

Left it running for 20mins today but no change, but it did start first time on the kick. Guessing it must be the battery is too low, going to buy a charger.

 

Good option, but you'll probably find some corrosion on the plug connections up to the clocks as well if it's not been used for that long