after my controller blowing a couple of months ago, i bought a leisure battery to keep me going for a few days (connected pump straight to it)
but this new controller from cleaningspot (£100) actually charges the lesuire battery like a relay, so if you were like me, running straight from van battery and always wanted a charging relay, i would highly recommend it.
i did need help in where to put the wires, but now i dont have to worry about the battery running dead on a big com job or compact estate!