The battery in the back of my van keeps going flat , the green light on my controller keeps flashing green I've been told that means the battery is low on power , it's the 2nd time this has happened in a month , I've checked the reach n wash battery everything is tight but I could be wrong even on boost I have hardly any flow and when I do it cuts on and off , getting fed up now as this hadn't happened to any off my other vans , I've taken a photo so you guys can see , can you see anything wrong ? Thanks for you help