Can I add a battery to my solar fountain so it can charge up and work when not sunny?

Yes, you can order a Solar-On-Demand panel and battery pack or a whole kit with a pump from our parts dept. The solar panel will have an on/off switch and a battery pack that allows you to turn it on and run it during the day, or turn it off and charge it up during the day. After it's charged you can turn it on in the evening and the battery will run the pump.