I was going to point out that a voltage meter can tell you a whole lot about how much battery capacity you have left, but Larry seems to have beat me to it. If I had to choose one over the other (which I don't, my meter has an amps/volts switch on it), I'd rather have the voltage meter over an amps meter on my solar/battery system.
Worth pointing out is that different battery types have different charge voltages for different levels of charge. The values posted in Larry's chart appear to be for a traditional "flooded" battery; AGM battery peak voltages are somewhat (0.2 volts) lower.
[quote]Hello, this chart might be of interest when checking the battery voltage.
It would be a good idea to use a more accurate digital multimeter to calibrate your analog meter.