Review request for HKJ [Rechargeable Batteries]

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HKJ
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Barkuti wrote:

How are your battery queues doing, Henrik? Is there place for some 2800mAh max cell?

It is winding down, lately I have published fewer battery reviews due to that.

Barkuti wrote:
In the meantime I may look for some co-funding for the other cell (because Wink

?

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

Barkuti
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HKJ wrote:

?

To send you some of my previously mentioned cells, that is. Just looking for some shared interest. 

HKJ
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Barkuti wrote:

HKJ wrote:

?

To send you some of my previously mentioned cells, that is. Just looking for some shared interest. 

I am interested in that.

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

HKSJOSHUA_
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Anyone know who makes the manker 2600mah flat top battery? I know its just a rewrap but just curious as they retail for 18 dollars

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Hello!

Quick question aimed at Henrik, did you receive the VariCore 32700 LiFePO4 6500mAh (Gray) cells from AliExpress' store #1874160 (https://entemple.aliexpress.com/store/1874160)?

Oh! Wellp, nevermind really. Found this Shop2097037 with slightly better pricing, interesting cells and cell packs.

They're selling this weird LiitoKala branded li-ion 7200mAh Question 26800 cells with tabs, guess that is some electric vehicle market product (5C discharge rating). And I must also say, without a doubt, that 7200mAh in a 26800 is high energy density, beating PLB 5500mAh at least on paper.

Henrink, did you ever tested some electronic load like the following? (guess the answer is not yet)

 

https://www.aliexpress.com/item/32725711985.html

 

Had a different, more display fancy electronic load in my wishlist but people were reporting failure to disconnect load after voltage cut-off in it. This one has good reports, guess I would only need a battery holder to complement with it. 

 

 

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Found a cheaper sale for the 26800s in small quantities, without tabs and less overrated; just in case Henrik would want to test such weird cells: https://www.aliexpress.com/item/4000218361115.html

 

 

Does anyone knows what OEM could be manufacturing such spring rolls? 

Sun, 10/20/2019 - 08:49; Sun, 10/20/2019 - 09:13

HKJ
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Barkuti wrote:

Hello!


Quick question aimed at Henrik, did you receive the VariCore 32700 LiFePO4 6500mAh (Gray) cells from AliExpress’ store #1874160 (https://entemple.aliexpress.com/store/1874160)?

I got and tested the Varicore batteries some time ago.

Barkuti wrote:

Henrink, did you ever tested some electronic load like the following? (guess the answer is not yet)

I started on in once, but it died on me. The problem is when they use a single mosfet transistor, standard mosfets are not good at analog regulation and cannot handle anything like the rated power when doing that.

Barkuti wrote:

Found a cheaper sale for the 26800s in small quantities, without tabs and less overrated; just in case Henrik would want to test such weird cells: https://www.aliexpress.com/item/4000218361115.html

That cell is a problem, it will not fit in my battery holders, 70mm long is about maximum I can test.

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

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HKJ wrote:

Barkuti wrote:

Henrink, did you ever tested some electronic load like the following? (guess the answer is not yet)

I started on in once, but it died on me. The problem is when they use a single mosfet transistor, standard mosfets are not good at analog regulation and cannot handle anything like the rated power when doing that.

I guess it died once you tested it at some power level within theoretical specifications, do you remember how much was that?

HKJ wrote:

Barkuti wrote:

Found a cheaper sale for the 26800s in small quantities, without tabs and less overrated; just in case Henrik would want to test such weird cells: https://www.aliexpress.com/item/4000218361115.html

That cell is a problem, it will not fit in my battery holders, 70mm long is about maximum I can test.

 

Found a review of it: Queen Battery QB26800 6800mAh 20A - the big guy! @ Thunderheart Reviews

 

 

Nice battery holder, doesn't it? Big Smile 

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Barkuti wrote:

I guess it died once you tested it at some power level within theoretical specifications, do you remember how much was that?

It was close to maximum rated power.

Barkuti wrote:

Nice battery holder, doesn’t it? Big Smile 

It is similar to the ones I used before.

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

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I bought some aaa batteries from ebay. The picture showed contour batteries. I think this is a good company which closed down or something…when they arrived they were Digimax. I discharged then charged them at 200mA in an Accupower IQ328 and two of them kept fluctuating between 1.41v and 1.42v. I ended up stopping the charge after 5 and a half hours! I know the current should be at least 0.3C but I wasn’t expecting this from brand new batteries. I always select the lowest current for new cells and when condition cells.

4 AAA batteries

Hobbyfotograaf
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Today i tested the “7000mAh” LiFePo4 cells after they are used for more than 10 months in the solar powered light. https://nl.aliexpress.com/item/32878468860.html?spm=a2g0z.10010108.10000...
According to the HTRC B6V6 balance charger the discharge capacity of the 2S battery pack is still 6459mAh (about the same as in the first test, almost one year ago).

The balance board does not balance the cells, but that is no problem because charging and balancing the battery pack after taking it off the wall took only 4 minutes and 2 seconds
(The cells were charged and balanced before capacity test.)
If there would have been a large difference between the two cells, the charge/balancing time would have taken much longer than 4 minutes.

These cells are much better than the Original lead-acid bettery that became useless after about one year.
A new 6V/4A lead acid battery is also more expensive than these cells + the protection board.
The LiFePo4 cells are still like new, it looks like they will last many years in that solar powered light.

I like the tests of new cells, but i am also interested in re-tests after they have been used in “real life conditions”.
I know it is very difficult to do that, but in this case i will continue testing these cells once a year

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Hobbyfotograaf wrote:

The balance board does not balance the cells, but that is no problem because charging and balancing the battery pack after taking it off the wall took only 4 minutes and 2 seconds
(The cells were charged and balanced before capacity test.)
If there would have been a large difference between the two cells, the charge/balancing time would have taken much longer than 4 minutes.

In my experience balance boards are designed to start resistor draining the cells at some overvoltage (overcharge) point. This, in my opinion, is a simple but effectively useless approach as overvoltage hastens cell damage (you want your cells to live long, not to die soon).

To keep cells in balance manually I would install voltmeters and pushbutton enabled bleeding resistors at each battery stage.

baustelle
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Hello HKJ,

 

Have you planned to test the upgraded version of the formerly reviewed Kentli or the AAA version?

https://www.aliexpress.com/item/32798542354.html

https://www.aliexpress.com/item/32798806801.html

HKJ
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baustelle wrote:

Hello HKJ,


 


Have you planned to test the upgraded version of the formerly reviewed Kentli or the AAA version?


https://www.aliexpress.com/item/32798542354.html


https://www.aliexpress.com/item/32798806801.html

Not really, but now you asked I decided to order them.

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

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