[Bernie Wolfard]

How do you tell if your battery is a good one and how to do track your batteries ability to discharge as they age? Several Lipo chargers can also measure battery resistance. The ones I know of are several Hyperion and NeuEnergy chargers. I am sure there are more that have this feature, I am just not aware of them. Internal resistance is what controls a C-Rating, the lower the internal resistance the faster the battery can discharge before it overheats. A batteries internal resistance (C-Rating) also determines the amount of ripple current the controller will have to deal with. The lower the batteries internal resistance the better the battery. With one of these chargers you can simply plug the battery in and records its resistance. The lower the number, the better the battery. If you track a batteries internal resistance over time you will see its resistance going up as the battery reaches the end of its lifespan.

With a charger that measures internal resistance it is interesting to plug in different packs of the same size and type from the same battery seller and see how different they are. If you do this you will find that the better battery companies have much less variance in their batteries because they QC the cells they use. You can also go through several cheap batteries and separate the good from the bad. Another interesting thing to track by measuring internal resistance is how many good cycles you can get out of specific packs. Again, you will find that the better batteries (except for bleeding edge supper high discharge cells, which typically don't last very long) will last much longer than cheapos. If you then calculate cost per run you will find the more expensive better packs are actually much less expensive in the long run.

The equipment it takes to measure battery internal resistance makes doing it yourself expensive and impractical, but it can be an easy job for a charger. Look for this feature in your next charger.

Bernie