Niner, the screwy 31 has not given up yet. It powered a ARB fridge 24 AH's worth, over 45 hours, and just took 45 amps initially from a new PD9245.
Profdant, I bought a cheap Ammeter voltmeter combo with included shunt. It just arrived today.
I hooked it to the 24 Ah depleted screwy 31 and then plugged in the PD9245. While the Ammeter/Vmeter combo has two calibration pots, I found they were already accurate on Volts and Amps.
http://www.amazon.com/DROK-4-5-30V-Digital-Display-Current/dp/B00GLKQOKI/ref=pd_sim_469_5?ie=UTF8&refRID=1PAVVGA9NT43X107TV5SAnother way to tell amp flow is with a clamp on Ammeter. One need not open the circuit as needed with a digital multimeter, just clamp the meter over one wire.
I use the Sears clamp on ammeter.
http://www.sears.com/craftsman-digital-clamp-on-ammeter/p-03482369000P clamp on ammeter.
The RC Wattmeter Niner linked is a clone of the 'watts up' meter. I have two of them, One mounted to my Meanwell power supply. Do note that they have thin leads and the 100 amp rating or the 130 amp ratings are for short bursts only
I removed the 12 awg aluminum leads and soldered on 8awg leads instead, and use 45 amp anderson Powerpoles. Hardly 100% accurate, I'd say 85% to 95%, but a great tool for monitoring, and counting, current, flowing in one direction.
I use the GTpower watt meter clone:
http://www.amazon.com/GT-Power-Analyzer-Consumption-Performance/dp/B00C1BZSYO I'd not pass more than 45 amps through it continuously, and only if the 12awg is upgraded. No more than 25 amps continuous without modification and perhaps that is generous.
