Looking for an easy way to test 18650 cells for internal resistance.
Here you go 
Can somebody move this to the noob questions thread?
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Some lipo chargers have that option. With the proper wiring you can know within seconds. No calculations needed.
Here my icharger in action measuring IR
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You can pick up a charger on Amazon for $20. It charges 4 batteries of different sizes/chemistry at specified amperages, and gives the capacity/internal resistance
One if the best small purchases you can make in my opinion
Edit: looks like the price went up? Still not awful though
18650 Battery Charger,MiBOXER Smart Universal 4-Bay Automatic LCD Display,Fast Charging Rechargeable Li-ion LiFePO4 Ni-MH Ni-Cd AA AAA C 26650 18350 17670 18700 21700 20700 RCR123,Fire Protection https://www.amazon.com/dp/B07H32WVTF/ref=cm_sw_r_cp_api_i_i7S4DbQVYZMR5
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Link, your recommendation is just taking up space without specifics.
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That’s pretty damn good internal resistance. Lowest I’ve seen from my lipo rc batteries was 0.7
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Lol my Littokita cells are between 24 milliohms and 212 milliohms…
There are some cell chargers that measure IR. I don’t know if I would trust the numbers in an absolute sense – it’s fine for relative stuff, like comparing cells or checking how cells are aging. I’m using a miboxer c8 (pretty cool device!)
https://www.amazon.com/Universal-Battery-Automatic-Rechargeable-Prevention/dp/B07QXP6XT3
I think I got mine fairly cheap through banggood and some secret discount code…
On the other extreme, this is probably the best way to measure
Note: hobbyking did an amazing team up with the designer of that device. You can read about it at rcgroups.com.
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