Author: John Muchow

What the hell is going on? How did it get like this?
As I work through finalizing the list of tests to perform on these LiPo battery packs, and how to best present the data, one thing has become very clear….most LiPo “C” ratings are complete fantasy.

Not just exaggerated but beyond comprehension as to how they could be set this high. They are obviously “pulse” ratings of some kind but even then they’re preposterous.

For example…
A very respected company has rated a pack in the 1800mAh range at 100C. That’s a rating of 180A. It has a DC internal resistance averaging of 42mOhms after break-in, very high. At 180A that means even when only pulsed, with a freshly charged 3S pack, the voltage drops from 12.6V to just over 5.0V instantly.

The minimum voltage is 9.0V for the pack. That 100C rating is utterly and completely useless and instantly brings each cell down to a level that can quickly damage it.

Another example of ratings silliness…
More than one of these 1800mAh packs has a C rating that results in a current rating above 117A. Why is that important? Because at 117A for more than a few seconds the 16AWG wire some packs use can melt…literally! Even if the current is pulsed the wires can reach VERY high temperatures, hundreds of degrees, at that current level. How can that possibly have been thought to be a rating, of any kind?

Another example…
The ThunderPower Rampage 70C pack (not in the table) has a continuous current rating of 126A, as listed on the Thunderpower web site. Even the 12AWG wire it uses will reach hundreds of degrees when used at that high a continuous current level and very high temperatures when pulsed. The voltage sag will be huge too. Just ridiculous.

Having said all this, the worst 1800mAh pack still outperforms the best pack we can make from 18650’s. I just want to inject a bit of sanity into the process of choosing a LiPo.

The table I’ve attached here shows the internal resistances of the 1800mAh packs I am testing. The names will be hidden until testing is done. You can see that two packs have very high internal resistance, a couple are fairly low, and the rest are in between. Interestingly, the lowest resistances do not belong to the packs with the best reputations. Quite the contrary in fact.

More info to come as the testing continues.

https://imgur.com/a/M6uZq

If you bought Samsung, Sony, LG, or Panasonic/Sanyo batteries then they probably came with stickers covering up the printing the manufacturer put on the battery wrap.

These stickers are added by the reseller/distributor, not the battery manufacturer, and is done to comply with shipping regulations. But these stickers keep us from verifying what batteries we actually have and interfere with checking their authenticity, a growing concern.

More than once a battery has had the wrong sticker put on it. There are at least four pink 18650’s, two browns, four reds, four blues, etc.

Taking off the sticker means you can verify that you got the battery you paid for. It’s also the first thing we’ll ask you to do if you have any questions about, or problems with, your battery.

So don’t hesitate to remove those stickers!

https://imgur.com/a/c0QsV

My thanks to ECR’s /u/icanshitposttoo for getting a pair of these batteries to me for examination and testing. These were bought from a smoke shop in Oregon, USA and are definitely fakes.

Here’s why:

– Genuine VTC4’s have three “legs” coming down from the top contact. These fakes have four.

– These fakes have the printing on the outside of an opaque wrap. Genuine VTC4’s use a translucent wrap and the text is printed on the metal can. The code square is printed on the wrap though.

– The printing on the fakes isn’t even close in appearance to the printing used on genuine VTC4’s.

– Discharging these fakes at 10A causes their voltage to drop to a useless level almost instantly. Genuine VTC4’s can be run for quite a while at 10A.

These fakes don’t match any Samsung, Sony, LG, or Panasonic/Sanyo battery I have. While I don’t have a sample of every battery made by those companies I think these fakes are of Chinese manufacture. They are either only rated a couple of amps or they are very low grade higher amp-rated batteries.

A troubling feature of these fake batteries is the use of a free-floating top insulating ring. Up until now every rewrapped and fake battery I have seen has used a self-adhesive ring. The counterfeiters are learning and we need to keep ahead of them. We can no longer assume that a battery with a free-floating ring is genuine.

One of the two fake VTC4’s I received seems to have either leaked from the top seal or vented before I received it. There is debris around and under the top contact. The 10A discharge test was done using the other fake.

If you have bought any of these fakes do not use them. Contact the vendor you purchased them from to arrange for a refund or exchange.

Please do not send me photos of your batteries asking me to authenticate them! Use the information here and, if needed, the photos in my test report for the VTC4:

https://www.e-cigarette-forum.com/forum/threads/sony-vtc4-2000mah-use-only-in-packs-18650-test-results-identical-to-other-genuine-vtc4s.733456/

https://imgur.com/a/qSshA

This makes for five different types of HG2 fakes and there will be more so be alert. My thanks to ECR’s /u/tarek26007 for posting pictures of his.

Luckily this version is easy to spot. It has a five “leg” top contact and not four like the genuine HG2 does. It also has an invalid date code, “O2O3”.

You can check the date code for a lot of batteries using the BatteryBro tool:
https://batterybro.com/pages/18650-date-code-lookup-tool

A valid date code does NOT mean it’s a genuine battery. They could have easily used a genuine code on their fakes.

Images of the fakes and a real HG2: https://imgur.com/a/Bq8Sk

Just because LiPo’s might have preposterously exaggerated ratings doesn’t mean they don’t still perform well against 18650’s.

My recent testing update post mentioned the wildly exaggerated ratings I saw for a couple of 3S 1800mAh LiPo packs. I received quite a few messages from people wondering how I can say that because they get great performance from their LiPo’s. And they should! Not meeting the 100C, 70C, or even the 50C ratings these packs have doesn’t mean they are lousy performers. It just means they don’t perform anywhere near their ratings. They can still be better than the 18650’s we use.

For example, see the graphs linked to below.

I tested two 3S 1800mAh-1850mAh LiPo packs against a 3S setup of Sony VTC5A batteries in a good quality battery sled at 10A, 20A, and 30Ap. Their DC internal resistances are:

Green LiPo = 0.028 ohms
Red LiPo = 0.044 ohms
VTC5A’s = 0.078 ohms

You can clearly see the difference the different internal resistances make. The higher the internal resistance, the greater the voltage sag and the lower the battery voltage is.

The Green LiPo is the clear winner here with the Red LiPo performing next best and the VTC5A’s performing the worst of the three. Interestingly, the Red LiPo is a very expensive pack from a very well respected manufacturer. The Green LiPo is slightly larger but is about half the cost and performs a lot better. I won’t be revealing the manufacturer’s name for either LiPo until I can test a second pack from each company to make sure my results are correct.

Neither LiPo performs anywhere near its ratings but in spite of that they still outperform a pack using one of the best 18650’s available.

There are safety issues when using LiPo’s though. I’ll be addressing these, and other considerations, when I have finished testing the rest of the 1800mAh-1850mAh LiPo packs. I hope to be able to do that within a couple of weeks.

https://imgur.com/a/fch74

Bottom Line: This rewrapped cell has an exaggerated current rating and is the same as the older rewrapped yellow/silver “35A 3000mAh” MXJO. When discharged continuously at its claimed 35A rating an internal protection device is triggered at around 100°C, permanently disabling the cell. This helps protect it from venting but renders the cell useless and means it cannot be rated a 35A cell.

WARNING: Do not assume that this internal protection device will prevent the cell from venting if you abuse this battery! It is not guaranteed to work and is only there as another possible layer of protection against using this cell at way above its rating.

This new yellow/silver wrap has “Type 2” above “20A CDC” in small print on the “back” of the cell. I assume that means Continuous Discharge Current. While I applaud MXJO for putting this rating on the wrap, it’s almost hidden and is essentially useless as very few people know what “CDC” means. In bold print on the front they have a meaningless 35A max or pulse rating with no mention of the continuous rating, which would be easy to add there. Even if they kept the continuous rating on the back of the cell they could have said “20A Continuous” or even “20A Cont.” and used much larger lettering.

These MXJO’s are identical in appearance and performance to the 15A/3000mAh Samsung 30Q. The 18650 ratings table has been updated to include this cell.

I’ve seen posts claiming that this MXJO was lasting twice as long as an HG2 or 30Q before needing to be charged. It cannot last longer than the cell that it is a rewrap of, the Samsung 30Q. If MXJO switches to a lower grade cell, always a risk with rewrapped batteries, it could last less.

The two cells tested were donated by Kai Chen from All Day Vapes (www.alldayvapes365.com). Thank you!

Test results, discharge graph, photos: https://www.e-cigarette-forum.com/forum/threads/mxjo-yellow-silver-35a-3000mah-18650-bench-retest-results-still-an-overrated-battery.779365/

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

18650 current ratings and safety grades: https://www.e-cigarette-forum.com/forum/blog-entry/18650-safety-grades-picking-a-safe-battery-to-vape-with.7447

Bottom Line: This rewrapped cell has exaggerated current and capacity ratings and is the same as the older yellow wrap “20A 3500mAh” MXJO. When discharged continuously at its claimed 20A rating an internal protection device is triggered at around 100°C, permanently disabling the cell. This helps protect it from venting but renders the cell useless and means it cannot be rated a 20A cell.

This new green/silver wrap has “Type 1” above “10A CDC” in small print on the “back” of the cell. I assume that means Continuous Discharge Current. While I applaud MXJO for putting this rating on the wrap, it’s almost hidden and is essentially useless as very few people know what “CDC” means. In bold print on the front they have a meaningless 20A max or pulse rating with no mention of the continuous rating, which would be easy to add there. Even if they kept the continuous rating on the back of the cell they could have said “10A Continuous” or even “10A Cont.” and used much larger lettering.

These MXJO’s are identical in appearance and performance to the 10A/3300mAh Panasonic NCR18650GA. The 18650 ratings table has been updated to include this cell.

The two cells tested were donated by Kai Chen from All Day Vapes (www.alldayvapes365.com). Thank you!

Test results, discharge graph, photos: https://www.e-cigarette-forum.com/forum/threads/mxjo-green-silver-20a-3500mah-18650-bench-test-results-still-an-11a-3300mah-battery.779095/

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

18650 current ratings and safety grades: https://www.e-cigarette-forum.com/forum/blog-entry/18650-safety-grades-picking-a-safe-battery-to-vape-with.7447

Bottom Line: This Kdest is just a rewrapped and overrated 10A 3400mAh cell. At its 15A continuous rating it was almost hot enough to boil water. Its “pulse” rating of 40A is ridiculously high and would bring the voltage down to uselessly low levels. Both of these Kdest cells were identical in performance and appearance to the LG MJ1.

Kdest has printed “MADE IN KDEST” on the metal can which is interesting considering that this is a rewrapped LG cell.

The 18650 ratings table has been updated to include this cell. The two cells were purchased directly from Kdest (http://www.kdest.com) for the purposes of testing.

Test results, discharge graph, photos: https://www.e-cigarette-forum.com/forum/threads/kdest-black-15a-3500mah-18650-bench-test-results-just-a-10a-3400mah-battery.778401/

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

18650 current ratings and safety grades: https://www.e-cigarette-forum.com/forum/blog-entry/18650-safety-grades-picking-a-safe-battery-to-vape-with.7447

Bottom Line: This “40A” Kdest is just a rewrapped and overrated 15A cell that can boil water at only 30A continuous. It reaches a dangerous temperature at 35A continuous. Its “pulse” rating of 80A is absurd and brings me to the point of apoplexy just thinking about it. The first pulse at that level would drop the cell’s voltage to under 2.5V….a less than useful voltage. Both of these Kdest cells were identical in performance and appearance to the Samsung 30Q.

Kdest has printed “MADE IN KDEST” on the metal can which is interesting considering that this is a rewrapped Samsung cell.

The 18650 ratings table has been updated to include this cell. The two cells were purchased directly from Kdest (http://www.kdest.com) for the purposes of testing.

Test results, discharge graph, photos: https://www.e-cigarette-forum.com/forum/threads/kdest-white-40a-3100mah-18650-bench-test-results-preposterously-overrated-absurd-pulse-rating.778265/

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

18650 current ratings and safety grades: https://www.e-cigarette-forum.com/forum/blog-entry/18650-safety-grades-picking-a-safe-battery-to-vape-with.7447

Bottom Line: This is a rewrapped and preposterously overrated 10A cell reaching 94°C at only 15A continuous and becoming useless at only 20A. Both Kdest cells were visually identical in performance and appearance to the LG MG1. This is the same cell that was used by Efest for the 10A version of their earlier “35A 3000mAh” cell.

Kdest has printed “MADE IN KDEST” on the metal can which is interesting considering that this is a rewrapped LG cell.

The 18650 ratings table has been updated to include this cell.

The two cells were purchased directly from Kdest (http://www.kdest.com) for the purposes of testing.

Test results, discharge graph, photos: https://www.e-cigarette-forum.com/forum/threads/kdest-beige-35a-2800mah-18650-bench-test-results-shamefully-overrated-just-a-10a-battery.778123/

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

18650 current ratings and safety grades: https://www.e-cigarette-forum.com/forum/blog-entry/18650-safety-grades-picking-a-safe-battery-to-vape-with.7447