Battery testing is a bit more complex than one would expect: A battery is based on chemical reactions, and the battery may be optimized for a specific use. Some batteries a very good at delivering low power for long periods of time, whereas other batteries can deliver more power over a short period of time, but will self-discharge over relatively short time.
Using the NXT brick and motors, a standardized NXT battery test platform could be built. The set has it all: A rather precise volt meter, a method to load the batteries, timing and a computer for logging, ...
To ensure usable and independent test results, a standardized platform needs to be built, and it needs to test batteries in a way that to some degree resembles the way a Mindstorms NXT robot uses power: A relatively high load over short periods of time.
To get repeatable test results, that can be compared between users, the following should be decided and standardized:
- A mechanical platform.
The platform must me stable, and it must be able to give a repeatable load. Another person building the device, must give the same results. The platform should be built from a standard NXT 1.0 or 2.0 set.
- A program performing the test.
The program should ideally be able to run in both standard and non-standard firmware with the same results.
- Environmental parameters.
Batteries are quite sensitive to temperature, so this should be taken into account.
I have a couple of ideas, but I would like some input from others...
Anyone up for the idea? Wanna know which batteries are the best value for money? Which are the best when money is no option? Are Duracells really better or worse than NiMH? How good are these Energizers really? (for LEGO Mindstorms, that is!)