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LiPo ESR Meter Mark II


Note that you can only edit the battery capacity to the nearest 100 mAH increment.  If you have a battery, such as 250 mAH, round it up or down to the nearest 100 mAH increment.  According to the owner's manual, it will have very little impact on the final results of your measurement. 

Now that the appropriate capacity value has been selected, connect the battery's balance lead to the meter. 

 

ESR screen 4

With the battery's balance lead connected to the meter, the display shows all the cells (in this case, I was using a 4 cell battery) on the screen along with the percent of charge, the total pack voltage, and the battery capacity.  At this point in time, the battery hasn't actually undergone any testing.  The meter is just displaying all of the voltages and settings for this test session. 

 

ESR screen 5

A press of the right button will test all of the cells in a fraction of a second and the results will be displayed on the screen as shown above.  The top line shows a FoM (Figure of Merit) value along with a very conservative C rating.  In this case, it shows a C rating of 19.  The second line displays the total pack voltage and maximum amps that can be safely drawn from the pack.  This value will always be the lowest cell maximum.  As they say, the battery is only as strong as its weakest cell.  All six cells can be displayed on the screen which makes it easy to compared them without having to scroll from one screen to the next. 

 

ESR screen 6 

A push of the left button switches the display from max cell amps to milliohms (resistance).  If you add the resistance of each cell, you'll notice that it falls short of the total pack resistance, which in this case is 33.4 milliohms.  The total pack resistance also accounts for the connector resistance and the battery leads.  The display will update about twice a second and it is not uncommon to see slight variations in the cell voltages.  Pressing the right button will repeat the test  After several tests of the battery have been performed, the average is displayed.

This is not the "end all tool" for determing which battery is the best one in the box.  It will certainly give you some insight as to the health of the battery and when used consistantly, give you trending data by which you can judge the performance of the battery.  Knowing when the well used battery should be shifted into a lighter duty model might very well give you notably better battery life and save a few dollars in the hobby budget. 

In closing, I hope this short review has provided you with some insight as to how the ESR meter works.  There is a lot of good information in the owner's manual and I encourage you to read it.  A number of things can impact the readings you obtain when using the ESR meter, with temperature being an important one.  The manual explains all of this which is why I highly recommend you read it in order to obtain the most accurate information when using your meter.

 

 

 

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