To measure the current draw of 120VAC appliances (under 10A), I use a homemade extension cord with a single-gang receptacle box on one end. Rather than go to the duplex outlet, the hot wire of the cord goes to a banana plug receptacle. Another banana plug receptacle is wired to the hot side of the duplex outlet.
My multimeter, with banana plug leads, plugs into the banana plug receptacles and all current going to anything plugged into the duplex outlet goes through the meter.
This is a great way to find out how much individual appliances are actually going to draw from an inverter or generator.
charge and discharge, I plan on getting a Link 10 amp-hour meter. Trace and Trimetic also make these, but they don't account for the Peukert Effect like the Link does.
Hope this helps,