Why not get a reel and have 60 metres of hose on it, treat the trolley as if it's a tank instead of a portable thing. So, sit the trolley on the ground next to your vehicle, plug your reel into its outlet and just walk to each property your cleaning with the hose in one hand whilst it's unreeling from the reel and pole in the other. Just like everyone with a fixed tank in the back of their van does. Wheeling a trolley around doubles the time used per clean. Total waste of time and effort.