Has anyone seen/used these Efest IMR 20A 18650 3100mAh Unprotected Rechargeable Li-Ion Battery - Flat Top ? That 20 amp rating, is it max continuous discharge? Would these be safe to use sub ohm (I usually build my drippers at .4) and/or in a DNA40 mod?
Purple Efest 3100mah 18650?
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Typically the only batts I use with my DNA30. I don't know if that 20A is pulse or continuous - and not even sure it is 20A - but hey they give me an all day vape easily. And without any issues over the dna board√ Btw, I'm using them for many months now.
Sweet! I'd never seen, or heard of the 3100mah before. I might have to pick up a few, but maybe I'll just leave them for my rDNA and just keep using my VTC5's for dripping...
P.S. Sweet Wizard!
Those work very well in a DNA30, they will go almost a day for me at 30watts ~12hours heavy useage
The button top version of that works for a few days in my Provari
The Efest 3100 is actually a 6.4A max. 18650.
http://www.e-cigarette-forum.com/fo...87759-purple-efest-18650-battery-warning.html
http://www.e-cigarette-forum.com/fo...87759-purple-efest-18650-battery-warning.html
My DNA30s go erratic with any batt which has lower than 10A discharge. With the Purple Efest 3100mAhs they work perfectly!
I don't think that's right TBH. If I had to guess I would say they were probably based on the Panasonic NCR18650-BD cell, which is rated at 3200mah and 10 Amp continuous discharge. They are not good for 20 A continuous discharge though. Despite overrating the discharge rate by two (typical Efest! And Keeppower do the same) they may have uncharacteristically underrated the capacity, compared to Panasonic.
Here are the discharge charts from lygte-info.dk of the Efest 3100 Mah Purple at 10 and 20 Amps, vs the Keeppower IMR3200 mah battery which is using the Panasonic cell mentioned. Note the trace is almost identical (differences could be explained by slight different batches or ages of batteries). IF they were based on the older Panasonic NCR18650A 3100 mah batteries (or I suspect the NCR18650BE rated at 6.4A), they would not be putting such a good voltage at 10A let alone 20A.
In fact batteries based on the NCR18650A (like this AW Black 3100mah) show significant voltage drop at 5A compared to the Efests
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Papa Lazarou,
The thread that I refer to shows a test done by dampfakkus.de which got the cells from two different Efest dealers:
https://translate.google.com/transl...=http://www.dampfakkus.de/akkutest.php?id=531
If you and I are referring to the same Efest 18650-3100, the charts by lygte-info.dk lead to another problem. It looks like Efest are using different cells for their re-wrapped 3100s for different batches. You simply won't know what kind of cell you are getting under the wrapper. It could be a 18650BE one time or a 18650BD on your next purchase. The same practice has been shown here in this thread:
http://www.e-cigarette-forum.com/fo...tery-other-than-vtc4-found-under-wrapper.html
I don't like the idea of buying batteries like buying a box of chocolates.
The thread that I refer to shows a test done by dampfakkus.de which got the cells from two different Efest dealers:
https://translate.google.com/transl...=http://www.dampfakkus.de/akkutest.php?id=531
If you and I are referring to the same Efest 18650-3100, the charts by lygte-info.dk lead to another problem. It looks like Efest are using different cells for their re-wrapped 3100s for different batches. You simply won't know what kind of cell you are getting under the wrapper. It could be a 18650BE one time or a 18650BD on your next purchase. The same practice has been shown here in this thread:
http://www.e-cigarette-forum.com/fo...tery-other-than-vtc4-found-under-wrapper.html
I don't like the idea of buying batteries like buying a box of chocolates.
Reasons I no longer purchase Efest batteries. Couldn't have said it better.
Hi pnyc. Did they confirm it was based on the NCR18650BE from unwrapping it and finding that underneath? I couldn't see that mentioned.
Also something puzzles me, on the Dampfakkus page they have 10A and 20A discharge tests. Would it be wise to do this on a battery you suspect to be unsafe above 6A or so?
This shows exactly what you'd expect of a NCR18650BD. It tracks the NCR18650PF (2900mah, 10 A max continuous rating) closely until the end when the extra capacity shows. It shows no sign of being pushed beyond it's limit here - no extreme voltage drop or loss of capacity.
Of course, it struggles at 20A discharge rates and gets hot - they are not intended for that high a current. Don't you think a 4A-6.4A rated battery would have reacted worse than this (and maybe blown) if discharged entirely at 20A?
The issue of Efest apparently not always being what they are supposed to be under the wrapper is worrying. At least in the case above they used a decent battery (LG HE2) instead of the Sony, but it's not what you want. I guess this is always a possibility with re-wrappers who don't have a rock solid reputation.
Also something puzzles me, on the Dampfakkus page they have 10A and 20A discharge tests. Would it be wise to do this on a battery you suspect to be unsafe above 6A or so?
This shows exactly what you'd expect of a NCR18650BD. It tracks the NCR18650PF (2900mah, 10 A max continuous rating) closely until the end when the extra capacity shows. It shows no sign of being pushed beyond it's limit here - no extreme voltage drop or loss of capacity.
Of course, it struggles at 20A discharge rates and gets hot - they are not intended for that high a current. Don't you think a 4A-6.4A rated battery would have reacted worse than this (and maybe blown) if discharged entirely at 20A?
The issue of Efest apparently not always being what they are supposed to be under the wrapper is worrying. At least in the case above they used a decent battery (LG HE2) instead of the Sony, but it's not what you want. I guess this is always a possibility with re-wrappers who don't have a rock solid reputation.
It was written in the test report (5th line in blue print):
Notes at bottom of the page:
EN: This cell is advertised as 20A. HOWEVER it is based on a Panasonic NCR18650BE All which is rated anywhere entre 4A and 6.4A max continuous discharge.
Notes at bottom of the page:
EN: This cell is advertised as 20A. HOWEVER it is based on a Panasonic NCR18650BE All which is rated anywhere entre 4A and 6.4A max continuous discharge.
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Great info guys! I appreciate the specs! The only part that sucks is that I missed the post that some of the 2500mah batts may not be up to specs, and I just picked up 2 at a local batt shop... Guess those will be just for regulated devices, no dripping lol... It would be sweet if a big company like Innokin could team up with a batt maker like Sony and design some batts specifically for vaping...
Vaping most popular batteries at typical low amp ratings isn't much of a danger. AW 18650 2000mah is a 10A continuous battery. I find the Purple Efest 2500mah batt to be in the same range of vaping time. The black and silver Efest 2250mah is in the same ballpark. I vape around 2.5A on a Provari and that's somewhere around 25% of rated continuous current on those batteries.
It's sub/low ohm use that stresses the batteries to the high amp ranges and you certainly need reliable high amp batts to do that. For most of us the 10A batteries are just fine.
This is a good reference. Scroll down to the discharge charts to compare batts.
http://lygte-info.dk/review/batteries2012/Common18650Summary UK.html
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List of Battery makes with their Discharge Rates and Safe Ohms:
https://docs.google.com/spreadsheet...01mUkl6RXNnM2o2R1E&f=true&noheader=true&gid=0
https://docs.google.com/spreadsheet...01mUkl6RXNnM2o2R1E&f=true&noheader=true&gid=0
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