Great batteries, Promatch, World Class, and Fusion, I have run them myself.
Though not conclusive, I have found that lets me know how my battery performs under a load is to do a static test.
You need a string of discharge bulbs, 20A to 30A, your choice.
A multi-meter of your choice (with a good battery in it)
A stop watch.
Pencil and paper.
Connect the discharge bulbs to a fully charged battery, I have an Auto-Cut off.
Then attach the multi-meter on the end of the discharge bulbs. (I have a pig-tail on mine with a Deans Plug, I stuff my multi-meter probes in the slots).
At the same time, press the button on the Auto-cut off to activate the bulbs and start the stop watch.
Record the voltage at 15 second increments on the paper.
You can use graph paper to chart these readings or get fancy and put them on a spread sheet.
All this will give a visual representation of what your battery is capable of doing at a specific time. Establishes a baseline to check your batteries performance against some time in the future. Also allows for comparison between batteries.
Your graph will indicate a heck of a lot of power at 0 to 15 (varies) dropping off rapidly between the 1st and 2nd minute (varies) and "levels" with a slow declining line to the 4-5 minute mark. At the end of run-time the battery will fall off rapidly again. I am only concerned how the battery performs for 4 1/2 minutes. At the end of 4 minutes my cheap battery packs are putting out 7.2 volts.
You then can visualize the rest, or actually see how it performs on the track. Again this is not conclusive, due to the variable loads on a motor during a race. But I find, it is a good place to start and helps be determine when to retire the pack and get a new one.
You can attach the multi-meter probes to the battery, the voltages will be slightly different, but the graph will be the same. I have found that for every tenth of voltage drop you loose 500+ rpm. But always do your testing the same way.
Lastly, you could be overgearing your motor and getting it toooooo hot! Heat plays hell on any electrics. Causes an increase in resistance, which ain't good! Be aware of compound resistance tolerances, hot battery, hot ESC, and a hot motor, equals more resistance.
Last edited by Hick; 06-15-2005 at 09:59 PM.