this is an old post but after having the g son over again today to pull batteries to check water levels I am pulling the trigger on this system. Flow-Rite MP 2000 Qwik Fill 12V Double Watering System. For the life of me I don't understand ( yes I do COST) why an RV mfgr makes doing routine battery maintance such a pain. My grandson will be happy to help install this system and get out from under pulling batteries every month to check the water