Help Required - AliExpress Lifepo4 battery dispute

Short_Shot

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pretty sure oreilys auto parts has free battery tester that will do a print out of battery specs.
Lol well.

Nice thought, but that's totally different than what we're doing here.

That will not give you a capacity test and I'm pretty sure it's not even safe to use on lithium.
 

Kman68

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Lol well.

Nice thought, but that's totally different than what we're doing here.

That will not give you a capacity test and I'm pretty sure it's not even safe to use on lithium.
And I don't fancy travelling to the US to do it anyway!
 

OffgridMNsystems

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Well I had a oreilys auto part have the print out showing ton specs based off batteries. One was ah reading. Showed 30 ah out of 70 ah rated battery. This was few years ago. It all depends tho what store. Some mainly have based good or bad test. Some have print out spec test. But ya lithium might not even work on test.
 

OffgridMNsystems

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Here tester that reads ah that you can see in top left corner
 

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Short_Shot

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Well I had a oreilys auto part have the print out showing ton specs based off batteries. One was ah reading. Showed 30 ah out of 70 ah rated battery. This was few years ago. It all depends tho what store. Some mainly have based good or bad test. Some have print out spec test. But ya lithium might not even work on test.
They can't possibly give you AH readings unless the test takes a substantial amount of time.

Pulling 1C from a battery takes an hour, an lead acid batteries should not be done at 1C.
 

DJSmiley

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Those meters don’t measure Ah’s, but you have to set them (or the cranking amps rating)

They measure the internal resistance and calculate the maximum cranking current based on this, and show a percentage of its rated capacity

Cranking amps determine (globally) the state of the battery, since those are the main factors for a starter motor.

Doesnt apply to lfp, you need to do an actual capacity test for proper measurements
 

OffgridMNsystems

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Well act scanner can do ah testing. Just not lithuim rated.
 

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Kman68

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This is the monitor I used that Aliexpress say isn't up to it 929444.jpg
Which is a little odd, as they sell them.
 

DJSmiley

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Aliexpress doesn't sell anything, it's a platform. Sales are done by sellers, just like someone using Amazon Marketplace to sell their products.
 

time2roll

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The battery finally turned up after 3 months, and I performed a capacity test, and it came out at about 81ah compared to the advertised 300ah. Quite a difference.
I assume the seller put in 4x 75 Ah cells and calls it 300 Ah. :(
 

koobs

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Look up the specification sheets of the high capacity LiFePO4 cells and look at the energy density. Use these sheets to prove the energy density of the chemistry and thereby claim fraud on the seller's advertised capacity. Or can just google some research papers on lithium energy density.
a standard 280Ah 3.2v cell from EVE weights about 5kg. So for that capacity you'd need 20kg in batteries alone.
The seller on their site claims 12v 300Ah, which is taken to be 300Ah at 12v, so the fraudulent intent is definitely there.
 

Kman68

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Been offered half my money back, and I keep the battery, OR all of it back, but I need to return the battery to China.

Given half the cost is £126, and it's £86 to send it to China, I'm wondering if I can be bothered to post it back.. for an extra £40.
 

Shale MacGregor

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It is unfortunate but that is a better result than some. If you have no use for it and sell it as a 100ah battery hopefully you could recoup more than what you would net by sending it back.
 

Kman68

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It is unfortunate but that is a better result than some. If you have no use for it and sell it as a 100ah battery hopefully you could recoup more than what you would net by sending it back.
yep. Feels like an offer I should accept, other than this effectively allows the company in China to make a profit from their fraudulent operation.
 

shavermcspud

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I don't mean to sound harsh as one UK guy to another, but did you not read the reviews for that battery and seller on the Aliexpress store from the link you sent, 90% of the reviews explicitly state that its nowhere near 300Ah the most someone got was 96Ah
 
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