Samsung INR18650-25R 2500mAh (Green) Ebay
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Official specifications:
- Type: Lithium-ion
- Composition: LiMn Hybrid (IMR)
- Rechargeable: Yes
- Positive terminal style: Flat top
- Protection: Unprotected
- Capacity: 2500mAh
- Max continuous discharge: 20A
- Nominal voltage: 3.7V
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Batteries marked Samsung from ebay.
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The two cells matches fairy well, i.e. it is probably new cells, but they cannot deliver more than about 10A and they are strained to do that.
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Conclusion
This is definitely not a Samsung INR18650-25R battery, it is some, probably old, low capacity cell and not designed for high current.
The cell works and would have been a acceptable cell about 10 years ago.
Notes and links
How is the test done and how to read the charts
How is a protected LiIon battery constructed
More about button top and flat top batteries
Graphical comparison to 18650 and other batteries
Table with all tested LiIon batteries