diy solar

diy solar

Just ordered Lifepo4 prismatic cell 3.2V 280Ah lithium lifepo4

My first of four cell purchases was through them. My impression is that the suppliers on Alibaba are (in general) both better and cheaper than those on Aliexpress. FWIW, one of the cells received from the supplier you mentioned arrived under 2 volts; however once charged it did test at full capacity.
 
Likewise, and I know of others who have received excellent cells since the reports of damaged cells. Let's hope that Basen just had a slip up in their quality control and are now taking steps to rectify the issue.
 
Likewise, and I know of others who have received excellent cells since the reports of damaged cells. Let's hope that Basen just had a slip up in their quality control and are now taking steps to rectify the issue.
they pack them prefect 20210119_125924.jpg
 
Ok, the dents and dings were definitely warranty type situations.

Glad to hear of more examples of good outcomes.

That packing looks great. Foam gap on all sides. Definitely do not envy whoever carry that box.
 
Ok, the dents and dings were definitely warranty type situations.

Glad to hear of more examples of good outcomes.

That packing looks great. Foam gap on all sides. Definitely do not envy whoever carry that box.
As this will be my first time buying cells why is it so bad if the cells have dents and dings on them?
 
@PsychoticEpisode, if the cells arrive in poor condition, but are advertised as 'Brand New, Grade A', then it's an outright lie.
We know that these are 'grey market' cells, but if the cells are not damaged and test near full capacity, then 'small' lies are tolerable.
'Truth in advertising' doesn't seem to be a concern to many (not all) of these vendors, so we have to be careful; 'caveat emptor'.

When dealing through Alibaba, ensure that your concerns are spelled out before purchasing, so you will have better leverage should there be a problem.
Asking for pictures of your cells before shipping used to seem a bit rude to me, but no longer, having been the recipient of poor quality goods.
As others have stated, if a price looks too good then the product is most likely of poor quality; using known vendors helps.
 
Sorry if the caution wasn’t clear, @Ale said it well.

Ensure you have a clear written communication of expectations. Do not be shy to ask questions about materials. Consider asking for measurements of the specific cells such as photos and or IR measurements.
 
As this will be my first time buying cells why is it so bad if the cells have dents and dings on them?
There are many classes of small dings and dents that do not represent a meaningful threat to safe operation or performing full specification. This is widely known.

For example.. 10mm diameter 0.1mm deep dent might not really mean much. But a 1.2mm diameter 0.6mm deep dent might mean oh crap. (btw these are random out of the air numbers not real numbers)

HOWEVER!

There ARE classes of dents or deformations of the casing that CAN cause unsafe operation or substandard performance.

Differentiating them is something I'm not an expert in. Each deformation requires some visual inspection firstly to document. It's good to take photos or record a video of all the cells you get. Something simple tripod cellphone camera with light enabled, and hold up each cell by hand and rotate to show all sides while recording video. That video, along with the serial number on the cell (if you can get it in the video this helps) or a personal tape and sharpie label can make diagnosing any problems later on easier.

It's paranoid to say ALL dings and dents warrant taking the cell out of service forever. But it's also unsafe to advise to ignore small dents categorically. All opinion, hope this might help you while dealing with the uncertain factors in the system.

A ding or dent will push the jelly roll layers together harder in one spot and that can cause problems like unsafe operation or less than 100% to specification performance. But again I'm not aware of a convenient model that allows you to with absolute certainty map between the geometric nature of the dent and an estimate of performance or safety degradation.

haha oops sorry for the wall of text. :coffee:
 
assembled. the case with spacers at each end providing compression at bottom and plastic coated all thread for top compression
View attachment 39508

I really like what you've done, here. It's an ingenious layout - and I'll be happy to mimic what I can.

Looking back - is there anything you might do differently next time?
 
I really like what you've done, here. It's an ingenious layout - and I'll be happy to mimic what I can.

Looking back - is there anything you might do differently next time?
no... I put vhb tape between the cells to lock then together and prevent shorting ...

I don't love pass thur main positive and negative couldn't get it very tight without breaking
 
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