Being able to measure the Internal Resistance of our batteries at any time without charging is a great benefit. They can be checked right before flight or right after flight or after they have been soaked at some standard temperature, thereby allowing improved comparisons of various batteries from different suppliers.
For the man who has everything.
This is a pretty specialized piece of equipment, since it ONLY measures the battery internal resistance. And it costs as much as a pretty good charger.
However, my experience is that while a LiPoly battery may show only a slight loss of capacity as it ages (both cycles and calendar months), the main problem is the increased resistance hurting the peak power. The pack does just fine on the slow discharge that most chargers can do, but the voltage drops so much under load that the ESC cuts out in just a few seconds of running time.
I compared this meter against the voltage drop in some actual motor runs and it seems pretty accurate. It does read about 50% higher than the ESR reading from my iCharger 306, but its also doing a much higher current load test than the charger does. (the short pulse, low current ESR of a battery is lower than it is with a higher load pulse)
The only thing I would change on this is to also have a balance tap connector with pins to fit the narrower Thunder Power connectors.
ESR Meter Submitted by Jim Oddino on 9/23/2011
works like it should! Submitted by Bob Parks on 9/17/2011