Mike showed me the proto at IRI. If you want a battery tester that will give you a good idea of the relative health of your battery and something that you can stick in your pocket, this is the item for you. We have used something I call the "mini-sun". It is a series of projector lamps that can be used for a battery load. Switch in as many as are needed for the load you want to test with.
For long term, repeatable battery testing with graphing and curve comparisons, you cannot beat the West Mountain CBAIII products. We test all batteries every year using a 7.5 amp discharge. The CBAIII connects to your computer through a USB port, connects a load to the battery, computes amp/hour capacity and displays a continuous discharge curve. This enables a user to see the relative capacity compared to previous years and other batteries while observing if one cell has less capacity than the others. They often will run holiday sales on their products. I have seen the $149 price-tag drop and may include free shipping. If you buy one please tell them you heard about their products from me and you are buying for a FIRST team. I am trying to get them involved with local teams. They are in Waukesha, WI.
http://www.westmountainradio.com/cba.php