Battery test: Efest IMR 18650 3100mAh 20A V2 (purple)

leaftye

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Jan 18, 2010
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[SIZE=+2]Packaging[/SIZE]

Outer box

Inner box


[SIZE=+2]Photos[/SIZE]
Top & bottom

Label:

[SIZE=+2]Discharging Graphs[/SIZE]

























[SIZE=+2]Charging Graphs[/SIZE]







[SIZE=+2]Notes[/SIZE]


The first photo shows that the wrapper doesn't extend to the end of the battery. This is a modification I made myself to ensure better contact during testing. ""Please do not do this modification as it may make it dangerous to use in your devices. These batteries are exclusively for testing, but if I were to use it for other purposes, I would rewrap the battery.

The batteries used in these tests have been provided by Covalence of Coval Vapes, a member of Reddit sub /r/electronic_cigarette with no exchange of money to either party.

To simplify testing and prevent mistakes, batteries in each test were charged at 0.5A and discharged to 2.80V.

The discharge tests from 0.2A to 5.0A are done an a Turnigy Reaktor, and discharge tests with higher current are done with a Maynuo M9712C DC external load.

These batteries are rated to 20A discharge. Unfortunately Efest does not say if that is a continuous or pulse rating. Based on the results in the 5A discharge tests, it must be a pulse rating, although I expected better results in the 10A discharge tests than I saw at 5A. I do not think it is suitable for the short pulses of high current used electronic cigarettes either. This graph shows that at 10A, 15A and 20A, the current drops to about 3.6V, 3.4V and 3.1V in approximately two seconds, respectively. I have previously noted that I do not vape, so my assumption may be incorrect. Please analyze the data for yourself and let me know what you think.

More battery tests. --- How to get more batteries tested.
 

leaftye

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Thanks. Hopefully I'll be able to get at least one more posted in the next day or two, but no promises because I'm moving next week. I have a few more tests done, and several wrapping up just before I move, and many more starting when I get to the new house.

They're all IMR batteries though, and there doesn't seem to be as much interest for those. Unfortunately I don't have any tests for protected batteries lined up.
 

oKtosiTe

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Thanks for the review!

Would it be safe to run a TM11 off of two of these? I'm looking an affordable way to gift away my TM11. :)
Do you have any insights? I've been thinking IMR's because they should be able to handle the current draw with less cells, and they're generally shorter...
 

leaftye

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Jan 18, 2010
Messages
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Thanks for the review!

Would it be safe to run a TM11 off of two of these? I'm looking an affordable way to gift away my TM11. :)
Do you have any insights? I've been thinking IMR's because they should be able to handle the current draw with less cells, and they're generally shorter...

I can't answer that definitively. I believe that would be close to 5A per cell, and these didn't run well at 5A. IMR's take a lot of abuse before venting though, so it would probably be safe. Can you test it yourself? Run it on the highest mode for twenty minutes, then quickly take out the batteries. If they're cool, they're probably fine.
 

oKtosiTe

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I can't answer that definitively. I believe that would be close to 5A per cell, and these didn't run well at 5A. IMR's take a lot of abuse before venting though, so it would probably be safe. Can you test it yourself? Run it on the highest mode for twenty minutes, then quickly take out the batteries. If they're cool, they're probably fine.

Heh. I think I'm better off just getting four protected ICR 2600s. :D
 
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