How can you accurately use an Ah-meter? How do you know what is the
starting point (after few hours loading capacity could be anywhere
between 70 and 100%)? How do you know how many Ah you battery can
really deliver? The real capasity depends on load and the rated
capasity is unlikely to be accurate.

Joakim

You initially charge up they batteries and set the starting point to zero.
Then all changing and discharging will be accurately accumulated. Battery
capacity is a spec given by the manufacturer or you can detrmine it
yourself if you have the patience. Capacity vs load is taken care of by
the use of Peukert's Equation which compensates for capacity vs
load. No, nothing is perfectly accurate, but it is way better than trying
top use voltage to determine level of charge. Technically, to get an
accurate reading you have to disconnect all loads and charging sources
and let the battery rest for 24 hours. Not really very practical.

Doug
s/v Callista