(17) Purple Efest Batteries not as Advertised

windxrunner;14039187 said:

Where are you guys getting this information about Efest batteries being not as advertised? I'm asking for some data that shows they aren't what they are advertised to be.

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Dampfakkus is an independent researcher in Germany who tests battery specifications, and who first exposed that Efest is using cells from other manufacturers, rebranding them, and then advertising over-rated specifications allegedly as a marketing ploy for better sales of their batteries.

Mooch brings to the table quite a few expert years of testing batteries for various businesses and some government projects. He mainly tests batteries for max temperature thresholds. Many know that heat is the enemy for a Lithium based battery -- get a battery too hot, bad things happen. Using a battery towards its max current output makes batteries get hot, damaging them and lowering their output and life cycle. His lists of tests can help you find the right battery for your application.

Hey, battery wrapping companies...


The purple Efest 2500mah "35 amp" battery:

Dampfakkus said:

This is a rebranded LG 18650HE2 cell. Careful: max continuous discharge rate for this cell is 20A *NOT* 35A as advertised by Efest. According to LGs spec sheet 35A is only permissible for short periods...

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DyVape said:

The IMR 18650 2500 mAh EFEST announced as 35A continuous discharge, are actually LG cells supporting a peak value of 35A but continuous discharge 20A.

This information is especially important for merchants who sell these batteries. We had already warned (about) the EFEST Purple 2500mAh batteries, announcing whimsical performance, especially in terms of continuous discharge, which can quickly be dangerous under certain conditions of use (low and very low resistance).

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The purple Efest 3100mah "20 amp" battery:

Dampfakkus said:

This battery is no way able of a 20A continuous discharge!

This cell is advertised as 20A. However it is based on a Panasonic NCR18650BE Which is rated anywhere in between 4A and 6.4A maximum continuous discharge. Performance test results put it on a level in between NCR128650B (6.5A) and Panasonic NCR18650PF (10A) and is doing fine there.

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DyVape said:

The IMR 18650 2500 mAh EFEST announced for the 35A continuous discharge, are actually LG cells supporting a peak value of 35A, but continuous discharge (of) 20A.

EFEST (has) recurred, this time in a more dangerous (way), announcing in labeling its 3100mAh battery continuous discharge 20A, thus supporting theoretically safely 0.25 ohm coils. Dampfakku showed that these Efest Purple 20A are actually Panasonic continuous discharge cells supporting 4A (!) And maximum (and therefore for a short duration), 6.4A limit for the atomizers in order to vape safely with these batteries is not 0.25 ohm but above 0.8ohm ... which makes a big difference. The cells used by EFEST 3100mAh "20A" are those of the Panasonic NCR18650BE.

Efest 3100mah 20 amp batteries: Warning - these batteries are dangerous.

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The purple Efest 2100mah 30 amp battery:


Unwrapping this Efest reveals a Sony VTC4 cell underneath

Dampfakkus said:

I am very sure this is in fact simply a rebranded Sony US18650VTC4 cell.
View attachment 369932

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Mooch said:

In my opinion, this is a 20A continuous discharge current (CDR) cell with average capacity for its rating. I recommend not using it above 25A as it runs at a very high temperature at those current levels.

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9-12-2015 As Mooch's bench tests are more recent than Dampfakkus's, I believe there's a good possibility that Efest is no longer using a Sony VTC4 cell in this battery. With Efest, you never know what cell is under the wrapper.



Purple Efest 18650 2100 mAh "38 Amp"

Mooch said:

This is only a 20A continuous discharge current (CDR) cell. At above 20A its voltage sags very low. At 30A or higher the cell is damaged by each discharge.

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The purple Efest 3000mah "35 Amp" battery

Mooch said:

• In my opinion, this cell's 35A rating is wildly exaggerated.

• But it is a great performing 20A continuous discharge current (CDR) high capacity cell. It is badly damaged at its 35A rating though.

• These Efest cells failed to meet the rating on their wraps by a huge margin.
• WARNING: Efest Purple 35A 3000mAh is now a 10A battery!

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[* Excuse the odd grammar in some of the above quotes. These were taken from Google translations from German or French converted to English.]

Efest does not "manufacture" their own cells, but rewrap original cells by other manufacturers and them sell them as their own brand. The cells that Efest are re-branding are good quality cells for the most part, but the deception Efest and their distributors use to market their batteries is what is dangerous. Please be aware that Efest may change what cell that they re-wrap at any point in time, so you may never know for sure what's "inside". UPDATE: The Efest 35A 3000mAh exists in at least 3 versions!

In summary:

People who are buying these batteries for sub-ohm use and expecting them to perform at the advertised spec may be unknowingly using a battery with inferior (lesser) specifications for that use, which could be dangerous by using a battery above its specification limits. The amp ratings that Efest is advertising are dubious and deceptive. Reputable manufacturers use the "continuous discharge rate" (CDR), an accepted industry standard.





Continuous Discharge Ratings vs Pulse (Burst) Discharge Ratings, Why You Need to Know the Difference

The "continuous discharge rating" in amps is the standard specification for amp limits within the battery industry. It is a determination made by the manufacturer and represents the amp limit a battery can be safely used before it will fail.

The "pulse or burst" discharge rating is not a specification standard within the battery industry. Every manufacturer or vendor seems to have their own definition of what the pulse rating is.

A pulse discharge rating is any use above the continuous discharge rating. It is never safe and not within the intended operating parameters of the battery. You should not operate your device above the continuous rating if you can help it. The pulse rating is a condition in which the battery is on basically a buildup to failure. It is exceeding the sustainable and intended discharge rate of the battery. It is inappropriate for a consumer device to operate in the pulse range of its battery.

Which would be why we shouldn't rely on any pulse rating. Any failure, mechanical or electronic, that fires the mod will operate in the 'continuous' mode. If your setup relies on a pulse rating, it's instantly over spec.

If your amp draw is safely in the continuous discharge range, your coil could act almost like a fuse and burn out before the battery is stressed. If you are already running the battery at the edge of it's limits (pulse), there is no margin of safety.

I am of the mindset that you should leave a margin of safety when deciding what resistance coil to use. We probably place too much faith into cheap ohm readers in being precise and accurate. Also, a RDA's post screw unknowingly coming loose can greatly change the coil's resistance.

Everyone is free to set their own parameters, and I can only say what mine are.

I try to never exceed 50% of the CDR (continuous discharge rating) of a fully charged battery (4.2v). So with a 20A batteries, that would be 10A. The above Ohm's Law Calculator tells me that a .4 ohm build is as low as I would want to use.

The reason that I place a 50% limit is because as a battery ages the mAh of the battery degrades, as the mAh degrades so does the batteries c rating (amp limit). So down the road, your 20A battery may only be a 10A battery.

Battery pulse ratings are useless! | E-Cigarette Forum