Watch out for FAKE Panasonic NCR18650B 3400mAh cells.

Miceeno

.
2020 3rd Place Winner
Joined
Nov 30, 2016
Messages
151
Likes
277
Portables
6
I just re-rebuilt my lawn mower battery pack. So I tested all the 18650 cells in my house. I found that I had bought 12 fake Panasonic NCR18650B 3400mAh cells. I wanted to share this information with the forum. The genuine cells are button top and the outer most wrapper is clear (usually priced around $20). The fakes are flat top and the outer most wrapper is green (usually priced around $16). Look at the pictures closely before you buy!

REAL Panasonic NCR18650B 3400mAh Tested Capacities:
3446
3433
3424
3408
3392
3366
3350
3312

FAKE Panasonic NCR18650B 3400mAh Tested Capacities:
2312
2298
2277
2233
2206
2201
2154
2141
1928
1914
1902
1877

REAL Panasonic NCR18650B 3400mAh

Real.jpg


FAKE Panasonic 18650B 3400mAh

FAKE.jpg


Also I'd like to point out a great source for good 18650 cells for a good price. Just like the hoverboard cells I shared in the past these are a while supplies last deal from Jehu Garcia. These cells are Samsung ICR18650-26F and they are $7 for 6 cells plus shipping.

https://jag35.com/products/6-cell-samsung-26f-18650-lithium-battery-pack

I bought 42 of these to add to my lawn mower battery pack. I upgraded from a 10s8p 17Ah to a 13s9p 20Ah battery. Their tested capacities are as follows:

Samasung ICR18650-26F 2600mAh
2936
2927
2891
2874
2862
2831
2781
2780
2778
2778
2776
2774
2774
2773
2772
2770
2768
2759
2752
2749
2749
2741
2741
2741
2740
2738
2734
2729
2727
2727
2724
2724
2719
2717
2712
2710
2706
2705
2704
2689
2660
2653
 
Last edited:

Miceeno

.
2020 3rd Place Winner
Joined
Nov 30, 2016
Messages
151
Likes
277
Portables
6
For the LOLs here's my new lawn mower battery. It's a 13s9p pack around 20Ah storing just under 1 kilowatt of power! I could have got away with a pack 1/4 the size but I overestimated my power draw.

I used 1/4 watt resistor legs to attach the cells to the bus bars. Not all 1/4 resistor legs are the same so they should be tested when being used as poor mans fuse wire. Out of the handful I tested they burn up around 5-7 amps. Fusing individual cells makes for an extremely safe battery, Tesla does basically the same thing. In addition to the fused cells I'm also running a 50 amp BMS.

This thing is amazing. My previous battery was a 10s8p. The problem was this was a 36 volt battery on a 48 volt mower. The blade never spun fast enough and it didn't have enough torque to cut tall grass. This is the problem with undervolting a motor. So I always had to keep the battery topped off to keep the voltage up for the cutting speed. With this new 48 volt pack I can mow anything. And because I don't have to keep it topped off I'm not charging it every single mow. In fact I've mowed for 4 weeks and the battery is only half depleted! I may only have to charge twice a year.


DSC01758.JPG


DSC01759.JPG
 

Ceirt

.
Joined
Apr 22, 2020
Messages
37
Likes
15
uhm i'm sorry to say this but... the first photo just show a protected battery

battery-protection-board-pcm-pcb.jpg

one way to see if the battery is real is looking at the datasheet and comparing the weight of the battery

Another one is checking out the production date on the battery
 

Miceeno

.
2020 3rd Place Winner
Joined
Nov 30, 2016
Messages
151
Likes
277
Portables
6
uhm i'm sorry to say this but... the first photo just show a protected battery

View attachment 12692
one way to see if the battery is real is looking at the datasheet and comparing the weight of the battery

Another one is checking out the production date on the battery

The best way tell if a cell is genuine is to test the capacity of the cell. I use both a LiitoKala Lii-500 and an IMAX B6 RC Charger. And I tested at both 1Amp and 0.5Amp draw rates on both battery charger/testers and got similar results. The 12 fakes I have were purchased in lots of 4 from 3 different sellers. Their capacities ranged from 1877mAh - 2312mAh. If a cell is advertised as 3400mAh and on average I'm only getting 2000mAh (60% capacity) I will call it fake.

As for flat vs button top, they are both protected. The button top has a user replaceable CID and the flat has an integrated CID. The CID is a current interrupt device. It's a diaphragm that separates from the positive side of the cell and the cell top.

Screenshot_12_1024x1024.jpg


Pictured is a flat top CID. If you Google "18650 CID reset" you can see people shoving screw drivers into the vents of a flat top cell to push the diaphragm down. If you want to try this yourself short an 18650 cell and it will spark and read 0 volts with no continuity from end to end. Then force the diaphragm flat with a screw driver. Now you should have a working unprotected fire hazard.

If you look at the pictures you will note the cells are different shades of green. And the cell wrappers are different material. In person the differences are more obvious. I attached those photo for more than the flat vs button comparison.
 

Ceirt

.
Joined
Apr 22, 2020
Messages
37
Likes
15
that why i said that checking for the weight is one way to see if it fake, i know that the best way to check it out is to actually test the battery, but not many users have a good charger (i didn't have one for alot of time xD).

what i'm trying to say here is... that using stock photos is not the best way to help new guys to check if their batteries are fake or not, hell i'm actually super new at this and trust me, it was hard to check if the battery was real.

in fact, as you have many batteries (that lawn mower battery looks awesome) i do ask you please, post some photos, size and weight from the real and fake batteries. i tried to buy 2 Panasonic NCR18650B but in the end i just bought 2 LG MJ1 because i couldn't find a reliave source for the ncr batteries.
 

Miceeno

.
2020 3rd Place Winner
Joined
Nov 30, 2016
Messages
151
Likes
277
Portables
6
Those stock photos are the same ones the sellers are using. And my fake cells are in my lawn mower battery (they are visible in the picture of the fuses). So I can't really get any better pictures or weights on them.

I used them in the lawn mower battery because they match my existing cells capacity better. Using RePackr.com I got the most balanced pack with minimal deviation using all my lower capacity cells. In my lawn mower, capacity is capacity, whether or not they are genuine. And there's enough protection in place if they do go rogue. As for a portable the most capacity in the smallest space is the goal. As well as it would be bad if one melted down in your hands.

In my testing 100% of the button tops have been real and 100% of the flat tops have been fake. So if the new guys only get that from the pictures than that's good enough for me. Spending an extra $1 per cell for the additional 40% of capacity is an excellent deal.

I also think that anybody who is playing with lithium cells should invest in a LiitoKala Lii-500. They are only $35ish and will save a trip to a burn center. Not only are they good for testing capacity they can be used to cycle the cells many times while you physically touch them to test for excess heat. The LiitoKala also gives you other good information for building batteries like internal resistance. I wrote an entire guide a while back about the importance of matching cells. And it's easier to match cells with a device like the LiitoKala than a kitchen scale.
 

Ceirt

.
Joined
Apr 22, 2020
Messages
37
Likes
15
i actually used the guide to buy my batteries (in fact, thanks for that!), that is why i started saying that i'm sorry to bother you about something you actually know more than me.

anyway, i have a miboxer C4 battery charger , and i have tried to buy a Lii-500 but i haven't found one in Chile (most sites says that is out of stock) , do you know a reliable site that ships them internationaly or to a US PO Box?
 
Joined
Nov 10, 2021
Messages
2
Likes
0
That's awful! I didn't think it would be so easy to come across a counterfeit. I recently bought a new mower, because a gardener is only as good as the tools they use. I haven't had to change the battery yet, but I'll consider your recommendations in the future. I think it is better to buy them in an official store, they give a warranty on their products. And if the seller suggests you buy them from him as a dealer, that's a reason to wonder about his honesty. Don't be too trusting; save your money and nerves.
 
Last edited:
Top