It's been a while since I filled the batteries that are part of our PV Solar system. We have 24 giant lead-acid L16's and they take about 8 gallons of water when they need to be topped off. Instead of using the old plastic watering can I decided to try a siphon system. This worked pretty well just using $3 in tubing combined with a little squeeze pump I found at a yard sale for $1. I'm transferring rain water from a 4.5 gallon plastic cubby.