Please fill both required fields - Cell IR and Capacity.
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Enter the Number as displayed below
Version 1.1
5-15-13
MRF
Lipoly Objective Performance Calculation Tool
Measured Cell IR =
<--- Enter cell measured internal resistance here.
If multi-cell pack, use highest measured cell value
Cell Capacity =
<--- Enter cell capacity in mAh units here
Figure of Merit (FOM) =
<--- Figure of Merit (FOM).
To be used as basis of comparison to other packs and to track pack performance over time
Max. Current (A) =
<--- Maximum recommended average current draw to prevent pack damage
Notes:
1.
To use calculator, simply insert the measured cell internal resistance and cell capacity in mAh into appropriate
(green)
cells.
To ensure highest possible accuracy of results, cell IR must be taken when cell has been allowed to settle at 72°F (22°C) for 1 hour minimum.
2.
FOM = Figure of Merit.
Figure of Merit is a calculation that uses measured cell internal resistance and normalizes it to cell capacity.
It is very useful when comparing packs of different sizes and from different manufacturers.
The larger the calculated FOM, the better.
For more background information on FOM, go here:
http://www.rcgroups.com/forums/showthread.php?t=1392662&page=1
3.
Maximum recommended current draw is a conservative calculation of maximum average current that one should stay within to limit possibility of damage due to overheating during discharge.
Use this value as an initial baseline and adjust if you find that temperature is within a reasonable value in your particular model.
Recommended maximum temperature for best longevity is no greater than 140 degrees F (60°C).
If you have some packs that have been evaluated using the tool be sure to share them on the data thread
→
There is a discussion thread about this method of estimating a sensible maximum average current here
→
Note that the display of "True C" that was in an earlier
version of the tool has been removed as some people were misinterpreting its significance.
You can easily calculate an equivalent C value for the recommended maximum current by dividing that current by the pack capacity in Amp Hours.
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