----- Original Message -----
From: "Dennis Pogson"

Connect it to an isolated, fully-charged cheap auto battery of known
capacity, and see how long it takes to discharge the battery. I assume
that
is what you want the data for in the first place. Not very accurate, but
hellish useful!


I do have a few 12v batteries ( I recently installed 6v,s) - using one of
them and monitoring the voltage could provide a rough measure of usage. If
the battery is (was?) say 100 Ah and the unit draws 50Ah/ day, I suppose I
would get a reasonable voltage drop if I let it run for say 12 hours
overnight?

GBM