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internal resistance, imax b6 v2

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internal resistance, imax b6 v2

Old 04-20-2022, 02:42 PM
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Default internal resistance, imax b6 v2

i just got myself a imax b6 v2.



the charger can measure the internal resistance of the cells. however the reading is very different than manually measuring it.





i took a few measurements with the b6 v2 (they're always a bit different with the same battery)



then, i measured the internal resistance manually using a 1ohm resistor and ohm's law and kirchhoff law.



what's your experience guys? can the b6 v2 mesure internal resistance of cells accuratly?
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Old 04-20-2022, 04:28 PM
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with that top quality product thats strange..lol
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Old 04-21-2022, 12:08 AM
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No two chargers have the same way of measuring internal resistance, just use it as a way of comparing your own packs, don't worry about comparing with other figures you see published.
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Old 04-21-2022, 11:42 AM
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Originally Posted by sosidge View Post
No two chargers have the same way of measuring internal resistance, just use it as a way of comparing your own packs, don't worry about comparing with other figures you see published.
published??

not sure i'm understanding what you're talking about.

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Old 04-23-2022, 05:39 PM
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I think he means comparing to other peoples numbers. Compare packs measured on your charger only.
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Old 04-23-2022, 05:52 PM
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and he can rely on these # how when every time he sees different #s
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Old 04-23-2022, 05:54 PM
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maybe he could add a few series of #s up and divide by the # count to get a average #
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Old 06-21-2022, 08:08 PM
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Default measuring Internal Resistance

when do you measure the internal resistance? At the beginning of the charge or at the end of charging?
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Old 06-23-2022, 01:08 PM
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i check ir b4 charge and after and keep track on post it notes on battery.
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Old 06-25-2022, 06:16 AM
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Whatever you do, just do it consistently. Temperature makes a big difference to IR. I have the benefit of having a basement which has fairly consistent temperatures all year round.

But I wouldn't get too wrapped up in IR. I've been testing my batteries every year for many years measuring both IR (icharger Duo) at end of charge as well as average voltage during a 5 min 20am discharge. IR doesn't tell the whole story. I can have 2 batteries of similar capacity, one with lower IR than the other, but the higher IR will perform better on the discharge test.

For sure when a battery gets a cell that's IR is 6+ milliohms you know it's bad, but I've retired lots of lipos that had IR in the 2s and 3s because they didn't perform well on the discharge test.
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