Just because I have been unemployed for 2.5 years does not mean that I can sit around on my butt. I was refilling the water level on 24 of our lead acid batteries at 8pm this evening. It is not difficult, but certainly uncomfortable and I always seem to get battery acid on myself in weird places. Today I think I got it on the back of my neck. These batteries store the energy from our PV solar panels and can sustain us for about 5 days (in theory) if we had no sunshine at all. My actual experience is that just to get these batteries to a raging boil and fully equalized takes one week of us switching over to grid power and not using the batteries at all.