Author: John Muchow

The archived webcasts and transcripts for the FDA’s Battery Safety Workshop that was held on April 19-20 are now available:

https://www.fda.gov/tobaccoproducts/newsevents/ucm535185.htm

If I hadn’t seen it I would never had believed it.
Efest’s new 20700, to be sampled soon, is being released with just a “Max continuous discharge” rating of 30A on the wrap and on the web site.

Efest 20700 specs screen capture: https://imgur.com/a/Tigby

Web page: http://www.efestpower.com/m/index.php?ac=article&at=read&did=468

If this is the Sanyo NCR20700A or the cell used by iJoy and Ampking, all true 30A cells, then this is very good news indeed! If this is just the 15A Sanyo NCR20700B then I will be very disappointed…to say the least.

Until recently, this Efest 20700 was shown (rendered) with a pulse rating on the wrap. I don’t know what changed Efest’s mind but I’m very happy they did.

I am hoping that this new Efest rating setup will be carried over to their 18650’s as our community sorely needs the companies other than Samsung/Sony/LG/Panasonic/Sanyo to accurately rate their batteries. Especially with the inevitable additional battery regulations coming our way over the next year or two.

I do not know yet when I will be testing these Efest 20700’s.
I do not know yet when or where they will be available for purchase.
As soon as I have any more information I will post it.

This Nitecore is a 15A rewrapped cell with a useless “pulse” rating (see the Comments section) and an exaggerated capacity rating.

It also has a useless 35A “max pulse discharge” rating on the wrap too. It also features “35A” in a huge font which many people will use as the cell’s rating when shopping or when a vendor displays it on their web site. For these reasons I feel the large “35A” rating, or any “pulse” or “max” rating, is misleading and shouldn’t be used.

If we vape with this battery above about 30A or so it can heat up to ridiculously high temperatures if there is a regulated mod malfunction or accidental button press in a mechanical mod. This could possibly force the battery to vent and leak/spray toxic organic solvents from the battery. I think vaper safety should be a priority when setting “pulse” ratings.

The wrap is not the standard heat shrink plastic. It is self-adhesive and appears to be similar to Mylar. I do not know how durable it is compared to the wraps being used now by other companies.

This cell says “IMR18650” on the wrap but it does not use IMR chemistry. It uses one of the INR chemistries.

I was especially disappointed to see this cell’s capacity rating set at 3100mAh by Nitecore. It is clearly set by Samsung at 3000mAh (see the 30Q datasheet image below).

I am rating this Nitecore at 15A and 3000mAh. The ones I tested were rewrapped Samsung 30Q’s. Their performance was essentially identical to the 30Q’s I have here.

The two cells that were tested were purchased by me from IMRBatteries.

Test results, discharge graph, photos: https://www.e-cigarette-forum.com/forum/threads/nitecore-35a-3100mah-18650-bench-test-results-only-20a-3000mah.803407/

All my test results to date: https://www.e-cigarette-forum.com/forum/blog-entry/list-of-battery-tests.7436/

This Nitecore is a 20A rewrapped cell with a useless and possibly dangerous “pulse” rating (see the Comments section).

While this cell has an exaggerated 25A continuous rating in micro print on the wrap it also has a useless 40A “max pulse discharge” rating on the wrap too. It also features “40A” in a huge font which many people will use as the cell’s rating when shopping or when a vendor displays it on their web site. For these reasons I feel the large “40A” rating, or any “pulse” or “max” rating, is misleading and shouldn’t be used.

If we vape with this battery above about 30A or so it can heat up to ridiculously high temperatures if there is a regulated mod malfunction or accidental button press in a mechanical mod. This could possibly force the battery to vent and leak/spray toxic organic solvents from the battery. I think vaper safety should be a priority when setting “pulse” ratings.

The wrap is not the standard heat shrink plastic. It is self-adhesive and appears to be similar to Mylar. I do not know how durable it is compared to the wraps being used now by other companies.

This cell says “IMR18650” on the wrap but it does not use IMR chemistry. It uses one of the INR chemistries.

I was especially disappointed to see this cell’s continuous current rating set at 25A by Nitecore. It is clearly set by Sony at 20A (see the VTC5 datasheet image below).

I am rating this Nitecore at 20A and 2600mAh. The ones I tested were rewrapped VTC5’s. Their performance was essentially identical to the VTC5’s I have here.

The two cells that were tested were purchased by me from IMRBatteries.

Test results, discharge graph, photos: https://www.e-cigarette-forum.com/forum/threads/nitecore-40a-2600mah-18650-bench-test-results-ridiculous-40a-rating-only-20a.803307/

All my test results to date: https://www.e-cigarette-forum.com/forum/blog-entry/list-of-battery-tests.7436/

This Nitecore is a 20A rewrapped cell with a useless pulse rating (see the Comments section).

While this cell has a 20A continuous rating in micro print on the wrap it has a useless 35A “max pulse discharge” rating on the wrap too. It also features “35A” in a huge font which many people will use as the cell’s rating when shopping or when a vendor displays it on their web site. For these reasons I feel the large “35A” rating, or any “pulse” or “max” rating, is misleading and shouldn’t be used.

The wrap is not the standard heat shrink plastic. It is self-adhesive and appears to be similar to Mylar. I do not know how durable it is compared to the wraps being used now by other companies.

This cell says “IMR18650” on the wrap but it does not use IMR chemistry. It uses one of the INR chemistries.

I am rating this Nitecore at 20A and 2500mAh. The ones I tested were rewrapped LG HE4’s. Their performance was close to, but a tiny bit worse than, the HE4’s I have here.

The two cells that were tested were purchased by me from IMRBatteries.

Test results, discharge graph, photos: https://www.e-cigarette-forum.com/forum/threads/nitecore-35a-2500mah-18650-bench-test-results-useless-35a-rating-only-20a.803145/

All my test results to date: https://www.e-cigarette-forum.com/forum/blog-entry/list-of-battery-tests.7436/

This Nitecore is a 23A rewrapped cell with a useless pulse rating (see the Comments section).

While this cell has a 20A continuous rating in micro print on the wrap it has a useless 38A “max pulse discharge” rating on the wrap too. It also features “38A” in a huge font which many people will use as the cell’s rating when shopping or when a vendor displays it on their web site. For these reasons I feel the large “38A” rating, or any “pulse” or “max” rating, is misleading and shouldn’t be used.

The wrap is not the standard heat shrink plastic. It is self-adhesive and appears to be similar to Mylar. I do not know how durable it is compared to the wraps being used now by other companies.

This cell says “IMR18650” on the wrap but it does not use IMR chemistry. It uses one of the INR chemistries.

I am rating this Nitecore at 23A and 2100mAh. The ones I tested were rewrapped Sony VTC4’s. Their performance was close to, but a bit worse than, the VTC4’s I have here.

The two cells that were tested were purchased by me from IMRBatteries.

Test results, discharge graph, photos: https://www.e-cigarette-forum.com/forum/threads/nitecore-38a-2100mah-18650-bench-test-results-useless-38a-rating-only-23a.802981/

All my test results to date: https://www.e-cigarette-forum.com/forum/blog-entry/list-of-battery-tests.7436/

This Nitecore is a 22A rewrapped cell with a useless pulse rating (see the Comments section).

While this cell has a 20A continuous rating in micro print on the wrap it has a useless 30A “max pulse discharge” rating on the wrap too. It also features “30A” in a huge font which many people will use as the cell’s rating when shopping or when a vendor displays it on their web site. For these reasons I feel the large “30A” rating, or any “pulse” or “max” rating, is misleading and shouldn’t be used.

I am rating this Nitecore at 22A and 2100mAh.  It appears to be a Samsung rewrap and might just be 2000mAh cells that test well for capacity. Its performance is similar to the 20R but its appearance isn’t a perfect match to the 20R’s I have.

The two cells that were tested were purchased by me from IMRBatteries.

Test results, discharge graph, photos: https://www.e-cigarette-forum.com/forum/threads/nitecore-30a-2100mah-18650-bench-test-results-useless-30a-rating-only-22a.802835/

All my test results to date: https://www.e-cigarette-forum.com/forum/blog-entry/list-of-battery-tests.7436/

I will no longer be saying a battery is accurately rated if the “pulse” rating is in huge numbers on the wrap, even if the accurate continuous current rating is also on the wrap in fine print.

This has been bothering me for a while but Nitecore has pushed me over the edge. While they have the continuous and (useless) pulse ratings spelled out it’s done in the tiniest of print while the pulse rating is repeated in huge numbers.

It’s clear to me that Nitecore, and other companies, want us to think that the pulse rating is the battery’s true rating. There are two problems with this…

1) Pulse ratings are utterly and completely useless unless we know some things about how the ratings were set. There are no standards for a pulse rating. Without knowing the length of the pulse, the time between pulses, and the criteria used to set the rating (temperature? run time? voltage sag? a combination of these?) we can’t compare one battery’s pulse rating against another’s. They’re useless.

2) These “pulse” ratings can be dangerously high. While you might normally be able to vape at that high a level without too much risk, since the current is pulsed, these ratings don’t take our safety into account in case of a mod malfunction or accidental button press. This can cause the battery to be discharged continuously, possibly causing it to vent (most likely not go into thermal runaway and burst though).

From now on whatever number is the most prominent one on the wrap will be the one I use as its claimed rating. This will be handled on a case by case basis and might need to be adjusted as a policy as testing continues.

Batteries that list both ratings equally, e.g., “20A/40A”, will have their useless pulse ratings mentioned but the first number will be considered as the continuous current rating.

This is not a perfect system and I’m sure it will need to be tweaked at some point but it’s a step that needed to be taken now due to the way these companies are presenting their ratings on the wrap.

Examples: https://imgur.com/a/dyuY8

This Cylaid is a slightly overrated cell with a useless pulse rating. It matches the Samsung 35E in both appearance and in performance.

While this cell has the claimed 10A rating in fine print on the wrap it has a useless 20A “max pulse discharge” rating on the wrap too. It also features “20A” in a larger font which many people will use as the cell’s rating when shopping or when a vendor displays it on their web site. For these reasons I feel the large “20A” rating, or any “pulse” or “max” rating, is misleading and shouldn’t be used.

I am rating this Cylaid at 8A and 3500mAh.

My thanks to Cylaid for donating the two cells for testing! (https://cylaid18650.en.alibaba.com)

Test results, discharge graph, photos: https://www.e-cigarette-forum.com/forum/threads/cylaid-10a-3500mah-18650-bench-test-results-a-rewrapped-8a-battery.801091/

All my test results to date: https://www.e-cigarette-forum.com/forum/blog-entry/list-of-battery-tests.7436/

This Cylaid is an overrated cell with a useless pulse rating. It matches the Sony VTC6 in both appearance and in performance.

While this cell has the claimed 25A rating in fine print on the wrap it has an even more useless 40A “max pulse discharge” rating on the wrap too. It also features “40A” in a larger font which many people will use as the cell’s rating when shopping or when a vendor displays it on their web site. For these reasons I feel the large “40A” rating, or any “pulse” rating, is misleading and shouldn’t be used.

I am rating this Cylaid at 15A and 3000mAh.

My thanks to Cylaid for donating the two cells for testing! (https://cylaid18650.en.alibaba.com)

Test results, discharge graph, photos: https://www.e-cigarette-forum.com/forum/threads/cylaid-25a-3000mah-18650-bench-test-results-just-an-overrated-20a-battery.800861/

All my test results to date: https://www.e-cigarette-forum.com/forum/blog-entry/list-of-battery-tests.7436/