diy solar

diy solar

My purchase of 16 cells at Alibaba - Dongguan Lightning New Energy Technology Co,

~Yuri~

New Member
Joined
Apr 13, 2021
Messages
39
So, I decided to create a new topic about buying cells for alibaba.
The background is as follows.
I have not been very successful in ordering EVE slots in the Bassen. No one there was in a hurry to send me the ordered cells, all the deadlines for sending were over, and even more, and I decided that I had to return the money and try my luck elsewhere.
On this forum, thanks to him for that, I found a review about Dongguan Lightning New Energy Technology Co, and specifically about the seller / manager of Hayley miu.
I liked the review and decided to try my luck there.
Hayley is a very nice girl and I reached out to her specifically. And I was not mistaken. She offered me CATL 300-310 Ah cells. And I decided to buy them, having discussed all the details. Exactly a month has passed since the date of dispatch, and now the cells have been delivered to me to the doorstep.
The packaging is great. Hayley was great. And I wrote to her that I was ready to kiss the girl if she was a little closer.
Well, the traditional small gift in the form of a keychain in a box is very cute,
Hayley! If you are reading, thank you so much for that! We are all human and we love these little things. As we say - a trifle, but very nice.
A few photos will be below. And now I am in the process of upper balancing at 3.64 - 3.65 Volts. To then measure the full capacity of the cells. Cell resistances are within 0.158 - 0.195 mils, voltage - 3.293 - 3.295. Only one cell was below 3.270 Volts. We will examine it additionally for an increased discharge - I will make the upper balance and in 3-4 weeks we will compare it with the rest. So far, the impressions are very positive, despite a few minor dents and a slight swelling of 3-4 cells. I am still studying the topic of cell contraction. Well, the upper balance and measuring the capacity will take some time. The cells are still of large capacity, and the charger draws 40 - 45 Amperes from me.
Discharge - 20 Amperes. So you have to be patient. And to you too, to get my test results.
All good!
P.S. Sorry for the mistakes - English is not my first language.
 
Last edited:
In the photo that shows all of the cells in a row, it appears the plastic wrapper is different color on some cells. Are these new cells? "...a slight swelling of 3-4 cells." sounds like not new.
 
In the photo that shows all of the cells in a row, it appears the plastic wrapper is different color on some cells. Are these new cells? "...a slight swelling of 3-4 cells." sounds like not new.
My dear, it’s time to understand that the cells are new, and even CATL, you will not buy at such a price. And don't buy it at all. Cells from disassembly, and everyone who wanted to know this already knows. Everything is worth the money. Read more and more often the forum, and a lot will open your eyes. And for new cells from EVE, you can contact Amy Wan. There are topics on the forum.
But why do you need it?
 
Well, I finished the full capacity test of cell number 3.
Discharging to 2.8 volts (95% SOC) showed that the cell has a capacity of 294.5 Ah.
If converted to 100%, the capacity is exactly 310 Ah. Strange coincidence, isn't it? Like a drugstore. I don't believe it. Here's a screen shot.
I will now put the next cell to discharge to 2.5 volts. So as not to divide/multiply.
Because according to the tables of smart people, 2.8 volts is 95%, 2.5 volts is 100% SOC.
 

Attachments

  • Ячейка №3_разряд до 2,8 Вольт (95%).jpg
    Ячейка №3_разряд до 2,8 Вольт (95%).jpg
    197.1 KB · Views: 24
The test of the second cell from my batch is complete.
317.7 Ah. I can only say one thing - I am satisfied.
Will be testing two or three more cells to choose from later. I don't have the patience for all 16 :)
One test goes for 15-16 hours.
The second test I limited the voltage below to 2.5 volts.
The result is below, in the screenshot.
Hayley, I know you will be reading.
Thank you so much for your purchase!
These are the kind of people you can work with. I made no mistake.
Believing in people is inspiring!
 

Attachments

  • Ячейка № 7 до 2,5В.jpg
    Ячейка № 7 до 2,5В.jpg
    196.3 KB · Views: 14
Cell #13 had a bad surprise - its capacity was 296.1 Ah. Sad, sad, sad. Since the battery is evaluated by the lowest cell capacity, I will not get a high capacity, although there are 317 Ah cells. Too bad.
I'll keep running tests. I checked cell 13 twice, in order to avoid mistakes.
I only checked 5 cells out of 16 so far, selectively.
 

Attachments

  • ячейка 13_дубль 2.jpg
    ячейка 13_дубль 2.jpg
    196 KB · Views: 10
Cell #13 had a bad surprise - its capacity was 296.1 Ah. Sad, sad, sad. Since the battery is evaluated by the lowest cell capacity, I will not get a high capacity, although there are 317 Ah cells. Too bad.
I'll keep running tests. I checked cell 13 twice, in order to avoid mistakes.
I only checked 5 cells out of 16 so far, selectively.
What is the battery self discharge rate?
 
Cell #13 had a bad surprise - its capacity was 296.1 Ah. Sad, sad, sad. Since the battery is evaluated by the lowest cell capacity, I will not get a high capacity, although there are 317 Ah cells. Too bad.
I'll keep running tests. I checked cell 13 twice, in order to avoid mistakes.
I only checked 5 cells out of 16 so far, selectively.
Nothing to be sad about in my opinion
 
I'll try to show you here what compression spring tensioning device I have constructed. The photo is a test version. It is assembled for testing. And the test was successful, I am satisfied.
 

Attachments

  • 20210604_200157.jpg
    20210604_200157.jpg
    158 KB · Views: 69
  • 20210604_200149.jpg
    20210604_200149.jpg
    161.3 KB · Views: 65
  • 20210604_200135.jpg
    20210604_200135.jpg
    92.6 KB · Views: 49
  • 20210604_200128.jpg
    20210604_200128.jpg
    69.6 KB · Views: 49
  • 20210604_200058.jpg
    20210604_200058.jpg
    173.2 KB · Views: 66
I'll try to show you here what compression spring tensioning device I have constructed. The photo is a test version. It is assembled for testing. And the test was successful, I am satisfied.
Would you please post your compression assembly over here ..... and maybe some details about the springs you used?
 
It seems you have been breaking into my garage...

If i posted up the last month of what I have been through it is EXACTLY the same...
I bought 8 cells from Hayley.... 1 was a different colour & slightly less capacity... 7 were over the stated 300Ah capacity
i also did a spring setup very similar to yours :)

So yes - Hayley was spectacular!
all cells are great & as advertised, for a superb price too.
 
It seems you have been breaking into my garage...

If i posted up the last month of what I have been through it is EXACTLY the same...
I bought 8 cells from Hayley.... 1 was a different colour & slightly less capacity... 7 were over the stated 300Ah capacity
i also did a spring setup very similar to yours :)

So yes - Hayley was spectacular!
all cells are great & as advertised, for a superb price too.
Truly we all live in one big world, and it is one! :)
 
more than a year since I last posted. The cells I bought from Haley are working in the best way possible. No self-discharge is out of the question. They hold the voltage well, the kind of power source one can only dream of for those who do not yet have one. The BMS SEPLOS with its well-known problem with the D4 diode spoiled the impression a bit, but that is another story, it has nothing to do with the cells.

So, the flight continues :).
 

Attachments

  • 20220527_092242.jpg
    20220527_092242.jpg
    159.5 KB · Views: 24
  • 20220527_092223.jpg
    20220527_092223.jpg
    153.3 KB · Views: 24
  • 20220527_092303.jpg
    20220527_092303.jpg
    160.3 KB · Views: 24
Last edited:
Прошло больше года с момента моей последней публикации. Ячейки, которые я купил у Хейли, работают наилучшим образом. Ни о какой саморазрядке не может быть и речи. Они хорошо держат напряжение, о таком источнике питания можно только мечтать тем, у кого его еще нет. Немного подпортил впечатление BMS SEPLOS с его известной проблемой с диодом D4, но это уже другая история, к ячейкам это не имеет никакого отношения.
Итак, полет продолжается :).
I had a couple beers with dinner but I think my eye are playing tricks.?
 
Back
Top