battery charging

I have been looking at / researching what I can about batteries, solar-systems, wind-generators, wiring, etc for quite a few years now. I have been using a calculator to try to figure out what works in theory vs. what works in reality. This morning I found a quote that explains very well what...

I like to know $$ vs Life on Deep Cycle Batteries. I will only be using them for DC output devices such as lights, small water pumps. As I improve my system; my goal is to have some type of emergency power with an ac converter to run an item as large as window unit Air conditioner for an...