This is why I've kept all of the incandescent lamps in the bathroom after replacing with LED.
My goal on a load test is to hit a 20A load which can be an interesting mix of stuff if one doesn't have a carbon pile around. When I do this test its with the inverter On, running the TV and DIRECTV receiver. After that I mix and match various lights in the coach to get me there, then the clock starts. I have an excel sheet that tracks Time, Voltage, and Current drawn off the batteries. I set a reminder alarm and check this every hour +- a few minutes. As the batteries are drawn down I'll change up to four lamps in the vanity to get the load back to 20A. I have a selection of lamps that range from 1/2A all the way to 4A each (x4 sockets) and that covers everything I need. When doing this load test on new batteries and if you want to get anal about it, better plan on a rather sleepless night because you are up every hour taking readings... My last one lasted over 23hours with new T-145's
In the end you can easily generate a very cool time tracked plot showing time, voltage, and current at any point along the reasonably constant discharge test. With a few buttons, excel generates this graph easily. Just so happens my evening load with all the usual stuff being on is just shy of 20A, so I can literally look at the plot and see what time I'm going to be in trouble. On the last test it was around 23hrs@20A.
Even though the Magnum SOC is very accurate, it still doesn't do time remaining.
