Basen 26650 4500mAh Issue ?

Batteries and Chargers Rechargeable Batteries
1

A few weeks ago I got a couple of Basen 26650 4500mAh.
I tested them and got the following results:

4249 mAh at 1A and 4171 mAh at 3A discharge current. Cut off voltage 2,9V.

I was a little bit disappointed about the result because in comparison with my Heter 26650 4500mAh (4616 mAh at 1A and 4587 mAh at 3A) the capacity seems to be rather low.
I accepted that so far.

Last week another couple of Basen 26650 arrived and, as usual, I tested them as well:

4944 mAh at 1A and 4835 mAh at 3A (exactly the same equipment and condition).

At first view those two lots I got look the same but I found two differences.

1.) The top end is different in diameter and height.
2.) The weight is different.

The manufacturer specification says 95g +–1g.

The second couple I got is within this specification, but the first couple has only about 88,3g both (those have lower capacity).

The one with lower weight and capacity on the left.

Weight within specification.

Low weight

I checked the security code on the Basen homepage. All four cells are reported as genuine, but I don´t know if this is reliable.

I am not sure what to do about this. Contact Basen and/or the seller (BG)?

Can any Basen 26650 owner please give me some feedback about look and weight of their cells ?

Anyway as they are unprotected I think it is not recommended to mix the cells and use them in series !

2

This is what I don't like about these 'name brand' batteries, that are just re-wraps, with a price premium attached.

It's not that they are inherently 'bad', but you don't know exactly what you are getting.

IDK - some of them may well be 'A' bin cells, & perform the best, but if the re-wrapper changes supplier, & sticks the same wrapper on them, it is a cause for concern, especially if an unwary person uses them in a series configuration.

3

I understand your concern. Vendor was a bit skeptical about its quality when I introduced them with BASEN in the beginning as well. Most buyers only purchased about 2-4pcs on average. This showed that they understood the risks that I had stated in the beginning of the group buy, and there were cautious of what they were buying.

At $7.80 price tag, I will not feel that BASEN 26650 cost the same as premium product in my opinion.

I would bring up JPLight's issue to vendor and see what BASEN has to say about it. Meanwhile, we welcome feedback from all exiting BASEN 26650 4500mAh owners.

4

I’ve got same ones as on this picture:

2 pieces bought at the group buy.

It looks to be the same one as Mooch has tested on ECF (https://www.e-cigarette-forum.com/forum/threads/26650-battery-bench-test-results-and-new-ratings-table.725452/)

5

Mine two both get around 4200mAh at 2A discharge. Quite disappointed.

6

JPLight, thanks for this input
I am still waiting on the Heters, ordered after your test at 5,50 a piece. Will test them when they are in.
Interesting to see how the manufacturer is going to handle this.

7

Thank you for your efforts, freeme. This will probably make things easier.

Yes, feedback from everybody effected is very welcome !
I don´t want to bump anything, but it could be really unpleasing for anybody who uses these in series and kills one of them or worse.

8

In a way it is. Same thing with my first lot.
But I think they are still doing a good job anyway, although having less capacity as declared.

9

My two Basens weighed in at 88g and 89g (rounded to the nearest gram on my postage scale).

I put both of them into my Liitokala Lii-500 for capacity testing. I’ll report back with the results tomorrow.

Note: The two Basen 26650s were ordered on 3/2/2016. I have another pair on order from 3/21/2016 which are en route.

10

Using the NOR option, 1A charge rate, 500mA discharge rate, the results from my Liitokala Lii-500 are 4292mAh and 4362mAh.

However, this is only the second and third charging cycles for these batteries. I’m presently cycling the batteries a couple of more times to see if there is any improvement.

11

You are only about 200 & 140 ma respectively off the claimed 4500 ma for the cell & as the Lii 500 only discharges the cells to about 3.0v I think the capacity is probably right as if they were discharged down to 2.5v you would see a few hundred more ma.

12

The Liitokala discharges down to 2.85V. Because of the steepness of the voltage drop once the batteries hit the 3.0V threshhold, I don’t believe there would be more than 50mAh gained by discharging down to 2.50V (from 2.85V).

2nd test results:

Running the Fast Test option, 1A charge rate, 500mA discharge rate, the results of my Liitokala Lii-500 was 4479mAh and 4497mAh. This was a significant improvement over the previous NOR Test results.

Note: The Fast Test option records the capacity of the cells based on charging cycle. The NOR Test option records the capacity of the cells based on the discharge cycle.

I’m running the NOR Test again, to check for consistency. If this third test matches the first test, then the differing results (between the first and second tests) may be attributed to the two different test methods. If the third test matches the second test, then the differing results might be caused by the new batteries breaking in.

13

What about the other aspect such as discharge current measured? How much better or worse if you compare to Keeppower, KK or other high drain 18650?

14

Good results then & pretty much as the manufacturer claims.

15

I’d like to, but it takes f … o … r … e … v … e … r to run these tests, given the relatively low charge/discharge rates and the relatively high capacity 26650 cells. Once I get done with the Basen cells, I can try measuring a few 18650’s. At least with the 18650’s, I can test 4 cells simultaneously.

EDIT: I wanted to test my Samsung 30Q’s anyway. Seems like there’s some controversy on the group buy thread about what the latest batch’s capacity is.

16

FYI.

Related discussion: [See post nos. 972 to 977]

17

i got 4 cells in white boxes. then later got 2 cells in colored “basen” boxes.
the 2 kinds have different tops.
is one better than the other.?
i guess i’m tired of the rewrap lottery.

18

Do you have a letter scale or kitchen scale? If so, weigh the batteries. The heavier ones seem to have a bit more capacity.
And, if you don’t mind, please report the results here

Otherwise, could you post pictures of your batteries (especially the positive terminal) for us to compare? Thanks!

19

Third test results and recap:

….Capacity Test No. …. Basen #1 Basen #2
….1. Normal …………… 4292mAh 4362mAh.
….2. Fast Test ……… … 4479mAh 4497mAh.
….3. Normal …………… 4318mAh 4397mAh

Liitokala Lii-500 charger, 1A charge rate, 500mA discharge rate, ambient temperature 68F to 82F.

The Normal Test is more consistent with the procedure that I am familiar with testing battery capacity: charge the battery until it is full, then measure the amount of current that it takes to fully discharge the battery. I am not familiar with the Fast Test methodology: discharge the battery until it is empty, then measure the amount of current that it takes to recharge the battery. HKJ’s review of the Liitokala Lii-500 also showed lower test results for the Normal Test, when compared with the Fast Test; but he didn’t seem concerned about the difference for li-ion cells. (This might have been due to the relatively small sampling. The variation might have been within the statistical deviation of test results.) However, he did comment on the difference being substantial when testing NiMH cells, and said that the Normal Test “looks more correct”. [Link to HKJ review]

20

The difference between charge and discharge capacity on LiIon will be small if done to exactly the same charge/discharge state, with NiMH it can be 50%.

Here is from my test log for a cell:
25/11-2015 21:44:28 Test: 0.2 Discharge (Ah, Wh):2,560, 9,632 rest v: 2.793
26/11-2015 01:53:05 After test: 0.2 Charged (Ah, Wh):2,575, 10,193 rest v: 4.169

26/11-2015 06:58:15 Test: 0.5 Discharge (Ah, Wh):2,543, 9,459 rest v: 2.794
26/11-2015 11:05:04 After test: 0.5 Charged (Ah, Wh):2,555, 10,107 rest v: 4.169

26/11-2015 13:36:02 Test: 1.0 Discharge (Ah, Wh):2,513, 9,190 rest v: 2.791
26/11-2015 17:40:55 After test: 1.0 Charged (Ah, Wh):2,525, 9,990 rest v: 4.169

26/11-2015 18:55:48 Test: 2.0 Discharge (Ah, Wh):2,496, 8,837 rest v: 2.794
26/11-2015 22:58:44 After test: 2.0 Charged (Ah, Wh):2,505, 9,915 rest v: 4.169

26/11-2015 23:48:42 Test: 3.0 Discharge (Ah, Wh):2,497, 8,574 rest v: 2.796
27/11-2015 03:51:35 After test: 3.0 Charged (Ah, Wh):2,506, 9,922 rest v: 4.169

27/11-2015 04:21:00 Test: 5.0 Discharge (Ah, Wh):2,451, 7,899 rest v: 2.794
27/11-2015 08:21:36 After test: 5.0 Charged (Ah, Wh):2,461, 9,770 rest v: 4.169

The largest difference is 15mA or 0.6% (I would not expect a “cheap” charger to be that precise).