Features
• 5A linear, 30A "Dyna-Pulse" discharge modes
• Ni-CD and Ni-MH compatible, 4- to 6-cells
• External leads for discharging stick packs (4-9 cells)
• Adjustable cutoff 0.2-1.0V
• Blue backlit LCD display
• Positive clamp-down 4- to 6-cell sub "C" pack holder
• Internal cooling fan
• Runs on 2 "AA" batteries

Testing
Obviously, to test a battery discharger you discharge a bunch of batteries. Along with my daily office routine, I had the DPD running practically all day long. Using my variety of 6-cell Ni-Cds and Ni-MH packs, I charged them all first, then discharged each one with the DPD. The DPD, unlike other active dischargers I've used, is self-contained and requires no external power source. Instead, the DPD does all of its goodness running off of two "AA" batteries. Usage of the DPD can be learned within seconds, thanks to the simple yet intuitive menus that flash on the brightly backlit LCD screen. You simply select discharge mode, tell the DPD if you're discharging a side-by-side pack inside the cradle or a stick pack (connected to the DPD externally by built-in alligator clips), select a cut-off voltage, and the DPD does the rest.
And do the rest it did. The DPD discharged all of my packs with little fuss, only beeping at the end to let me know that the job was done. The results screen gives a lot of information: discharge time, average voltage, capacity, and internal resistance--not only for the pack, but also for each individual cell. This is a plus when you're trying to see how balanced your high-dollar packs really are. The DPD's last recall feature is also a plus: Even if the unit has been turned off, with the push of a button you can get the results info from the last pack you discharged. Throughout testing I did run into instances where the DPD would only read 4 of the 6 cells in the cradle, but this was due to bad positioning of the pack. If you fit the pack properly into the molded cell recesses in the DPD, it will read all 6 cells fine.

Conclusion
For those of you who maintain your battery packs like it is a religion, you're going to definitely want to go check out the Trinity DPD. The $120 street price isn't an issue, given the wealth of information per individual cell that the DPD gives the user. Also consider that other active dischargers that are a few bucks less than the DPD require a separate power supply, so this could easily break past the DPD's price point. I'm happy to say that the Trinity DPD is a great and very useful discharger that is easy to work with and does a lot more than just blink lights at you!