Originally Posted by Ohmic
There are also commercial off the shelf products available. Sometimes surplus equipment can be found for reasonable prices.
Here is my super simple and adjustable battery load gadget, each bulb is 50watt (5amps at 10v) I use a little desk fan to cool the bulbs and the whole setup because at 25amp draw there is a lot of heat there.
I have since added an extra mount to give a total adjustable load up to 30amps, works really well.
My ESR meter arrived last week, I really love it, it along with the Emeter PC suite, is a great setup to test and log battery reliability.