Here is an inexpensive option for those trying to measure under 65 amp hours cumulative current in one direction only:
http://www.amazon.com/High-Precision-Power-Meter-Analyzer/dp/B00C596UIA/ref=cm_cr_pr_product_top
I put some Anderson powerpoles on mine and frequently hook it inline with various loads, or charging sources.
I have a Bluesky battery monitor tied in with my solar but the linked device above is a more enlightening tool when hooked to individual items.
Here is mine on my Vitrifrigo compressor fridge
VOltage charts when the battery is under load or just off a charging source is not accurate, and the surface charge right after driving leads to the belief that the alternator is some instant magical battery recharger.
Most people without some tool to measure alternator current overestimate its contribution by a huge factor, and those of us with the tools weep at the overall ineffectiveness of a 130 amp alternator giving the battery 7 whole amps when it could eat up 25amps from some other charging source