I also use the West Mountain CBA for testing though a low budget method does exist.... I us 50 watt,12 volt light bulbs made for RV use and they require 4 Amps (for 50 watts) per bulb and can serve as a load test ,over a time period ...to provide a near continuous load on the battery while a Voltmeter can be checked from time to time to get a good idea of battery capacity. For larger batteries I often use 3 or more bulbs OR I just use a medium size inverter to power a 120 volt lamp for 150,250,500 watts of test capacity and the test,though not an exact science ....is good enough for my use.