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cells that are more than original capacity?/
#1
hello
starting to test my recycled cells, im starting to find a few cells that are more than original capacity, some up to 200ma more than original capacity? their from branded cells like samsung and sanyo, is this normal?
Battery is li iron using 18650s, 14s, 0p, and growing cell so far 300, untesteded.
Bms is a diy open source by stuartpittaway.
No solar yet, 
Building wind turbine, 48v im after a 48v motor if anybody has one for sale.
Cells 2000 to 2500ma.
Cells 1500 to 2000ma.
Cells 1000 to 1500ma.
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#2
Please refer to this thead: https://secondlifestorage.com/showthread.php?tid=7987

And btw, it's mAh, not mA. mA is charge/discharge current, mAh is capacity.
Proceed with caution. Knowledge is Power! Literally! Cool 
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#3
does this mean they are damaged or can they be used? or recycle them a few times ?
Battery is li iron using 18650s, 14s, 0p, and growing cell so far 300, untesteded.
Bms is a diy open source by stuartpittaway.
No solar yet, 
Building wind turbine, 48v im after a 48v motor if anybody has one for sale.
Cells 2000 to 2500ma.
Cells 1500 to 2000ma.
Cells 1000 to 1500ma.
Reply
#4
(09-21-2019, 06:00 PM)Jonisingt35r Wrote: hello
starting to test my recycled cells, im starting to find a few cells that are more than original capacity, some up to 200ma more than original capacity? their from branded cells like samsung and sanyo, is this normal?

Just to be clear, is "original" referring to factory specifications or to a first test of a cell?
Jonisingt35r likes this post
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#5
yes higher than original capacity acording to the data sheet
Battery is li iron using 18650s, 14s, 0p, and growing cell so far 300, untesteded.
Bms is a diy open source by stuartpittaway.
No solar yet, 
Building wind turbine, 48v im after a 48v motor if anybody has one for sale.
Cells 2000 to 2500ma.
Cells 1500 to 2000ma.
Cells 1000 to 1500ma.
Reply
#6
1. Look at data sheet -> check battery capacity at discharge current (mA or C)
2 Check Your discharge current

Bigger discharge current = less battery capacity
Temperature also is matters
100kwh-hunter likes this post
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#7
Yes, it's not unusual. Quality brand name manufacturers generally understate and over deliver. They will make sure that customers receive cells that at the _minimum_ meets the capacity specified in the datasheet. Considering manufacturing tolerances, and that cells could sit in less than ideal conditions for months until reaching the customer, they generally build cells to exceed their specs by quite a bit.

Generics will often barely meet the spec sheet, while fakes (6000mAh 18650!) will significantly underperform.

Of course, your testing equipment may be inaccurate as well.
Korishan likes this post
Modular PowerShelf using 3D printed packs.  40kWh and growing.
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#8
(09-22-2019, 04:48 PM)Marrcin Wrote: 1. Look at data sheet -> check battery capacity at discharge current (mA or C)
2 Check Your discharge current

Bigger discharge current = less battery capacity
Temperature also is matters

The data sheet also specifies a low voltage cutoff. Some specify 2.5, while others specify 2.75.

Check out some of the Cells listed in Thunderheats reviews. The discharge graphs show the variations in capacity at different discharge rates.
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#9
(09-21-2019, 06:00 PM)Jonisingt35r Wrote: hello
starting to test my recycled cells, im starting to find a few cells that are more than original capacity, some up to 200ma more than original capacity? their from branded cells like samsung and sanyo, is this normal?

(09-23-2019, 02:47 AM)ajw22 Wrote: Of course, your testing equipment may be inaccurate as well.

Yes definitely testing equipment question.
What tester/ testers are you using?

A tester that has a 10% error to the high side will show a 2000mAh cell with 2200mAh as with the Zanflare.
Liitokala at least 5% so in this case a 2500mAh battery would possibly show 2625mAh.
Opus has a ~3% to the plus, Foxnovo is +- 2% SkyRC +- 1%.

So yes my first thought would be test equipment. and then ajw22s answer with good quality cells are generally "minimum" and "typical" mAh rated which could be a 150mAh to 200mAh spread.

Wolf
If 18 X 650 = 2200+mAh then we have power! 
May all your Cells have an IR of 75mΩ or less Smile
Last count as of 8/7/2019
Total Number of Cells Recorded and processed                 6149
Total Cells required for PowIRwall                                   2856
Total Cells ≥2200mAh, ≥80%, ≥35mΩ, ≤75mΩ, ≥4.12V   2760
For Info Google Drive
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