eBay and Aliexpress LiPo battery packs. Are they worth anything?

Bitmugger

Active Member
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Canada
I see shrink wrap bare 18650 battery packs on eBay and Aliexpress with absurd claims about mah and good prices. What can I really expect from these packs?

I see on eBay for $100cdn I can get a (as advertised) battery pack that is 48V 30Ah 13S3P.
Now that claim is laughable, it would mean each 18650 is about 30ah/3 = 10ah or 10000mah per battery which is like 3x+ better than chemistry allows right now.
I would guess the real value is like 2000mah to 2600mah per battery making the final battery pack more like 48v 6-7ah.

But I'd still pay $100 for a 48v 6ah battery. In fact I'd buy 3 and make a 18ah battery for $300 and be delighted. So what's the catch?
Do these battery packs fail on the BMS or is the cell quality so terrible they aren't worth buying? Will they fail after a few charges?

Has anyone tried these and what is your experience? I'd honestly like to buy three of the 52v packs that I'll call 6ah each and combine them to make a 52v 18ah pack for like $350cdn but what am I missing?
 
All battery claims apart from known manufacturers should be view sceptically

here is a comprehensive test of claims vs actual performance

 
Yeah the specs they all tout are garbage, I get that. I have little worry about the overall capacity, I am assuming very low-end on capacity but is it still a fools errand to buy these packs? Will they fail after a couple charges or any other gotchas with them? Even if they deliver just 5ah per 13s3p(48v)/14s3p(52v) pack I'd be happy as long as they can handle at least a couple hundred charge cycles.

I should mention my use case is I want an extra battery for occasional long range trips. I have a great battery now for daily use.
 
I think the greater concern may be whether or not they are built so poorly and with such cheap components that they fail in a dangerous manner
 
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I would guess the real value is like 2000mah to 2600mah per battery making the final battery pack more like 48v 6-7ah.

But I'd still pay $100 for a 48v 6ah battery. In fact I'd buy 3 and make a 18ah battery for $300 and be delighted. So what's the catch?
If the guy is already lying the big lie, why trust him to even use those 2300maH cells. Just stay away from the known liars.

However, I have bought three chinese shrink wrapped packs. They had more realistic ratings and I figured that if I got 80%, I'd be satisfied. So far, a 36V7aH pack that tested out at 5.6AH, a 36V6aH pack that tested at 4.6aH, and a 48V10aH pack using 21700 cells that I've not used yet. The first two were $70 and $90. and the last was $120. Hoping to see 8AH out of the last one.

Safety is a concern. The 48V pack is large/heavy so I added more padding and put it inside a box made out of coroplastic (used for lawn signs) with a second shrink wrapped layer., I store all of these inside cinder blocks with a patio paver on top,
 
I ended up ordering a Dorado battery via Aijiu Power, 25ah using Samsung 50E 21700 cells. Aijiu and their rep Jenny have been fantastic about answering questions and providing me assurances about the cells they use and photos of the manufacturing process. There's another thread here about the batteries, they can provide them in many formats, I am going to review the one I ordered when it arrives and put it through some extended rides and multiple charge cycles.
 
I ended up ordering a Dorado battery via Aijiu Power, 25ah using Samsung 50E 21700 cells. Aijiu and their rep Jenny have been fantastic about answering questions and providing me assurances about the cells they use and photos of the manufacturing process. There's another thread here about the batteries, they can provide them in many formats, I am going to review the one I ordered when it arrives and put it through some extended rides and multiple charge cycles.
Samsung cells. Takes your pack out of the category of cheap no-name. Should be good.
 
All battery claims apart from known manufacturers should be view sceptically

here is a comprehensive test of claims vs actual performance

That's an eye opener. If I had seen it before I probably wouldn't have bought the cheap batteries that I have from Amazon sellers. Only one of my cheap batteries was advertised to have Samsung cells, and who knows if those are counterfeit or not. But so far my cheap batteries have performed flawlessly including rides of 50-60+ miles and with remaining charge that would indicate 80+ miles possible (I ride without assist when I'm able).
 
I do know the Okoman 28Ah packs will barely do 6Ah. Measurement below At least I got my money back…. (Falsely advertised)
-BB

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What is it about China, that makes their claims so unreliable? Is somehow related to communism or lack of religion?

My opinion is that it's more a cultural difference and there's a lot of pressure to succeed, grow your business, make money and be prosperous in China. That push is there in the people and in business and in government.

When you are pressured to succeed there's several ways to do it:
1) Copy the success of others to save steps
2) Make your products more cheaply and charge less for more sales
3) Make your products of higher quality and charge more for higher profits
... probably more ways too

If you look at those options. #1 is something China does very well, if a product is popular it gets copied often inferior to the original but often equally as good as the original. #2 is the other common technique and China has huge manufacturing capabilities so as a vendor you have lots of choice for cheap components and lots of competition driving you to make things even cheaper. #3 is an option North American and European companies often take but is harder for a Chinese company, English isn't as widely spoken in China but is very common in business outside China and #3 requires more time, more investment in marketing, more business connections and is just a tougher road to follow.

Option #3 is happening in China though, you just need to find good vendors. Think of it as how post-war Japan was. Japan was a synonym for cheap manufacturing for years but slowly transitioned and known for quality now. That will happen to a greater or lesser degree with China too, just give it time, China is a very old country but a very young economy on the world stage.

What I don't agree with is that some people feel china = junk, it's not the case. Cheap stuff = junk, we just happen to want to pay less and less and buy the junk which doesn't leave much room for the quality items regardless of where they are made. Just my 2 cents.

I also want to note, I've hired dozens of foreign workers over the years and in my experience all immigrants I've encountered are very hard workers, but the Chinese people I've had the pleasure to work with were tremendously hard working, very committed to doing excellent work, very respectful and just amazing people to know and be friends with.
 
I have four cheap generic ebike batteries, two 48v and two 36v, and one very expensive Yamaha battery. They have all performed equally well as the Yamaha so far. Each of my cheap batteries cost less than a Yamaha charger alone. I'm mostly concerned about fire/explosion risk like reported on cell phones, tablets and hoverboards so I only charge them in a garage away from other stuff. Yet I don't recall any first hand reports of these ebike batteries burning or exploding on this forum nor on reviews of the specific batteries I have purchased. I'm sure there is a cut off where below a certain price only junk can be supplied but not so far with the batteries that I've paid as little as $160. I only ride bicycles for fun and exercise, not as an all consuming passion that seems to drive some of the members here who spend thousands on what, in the end, is just a recreational bicycle for the majority of riders.
 
My opinion is that it's more a cultural difference and there's a lot of pressure to succeed, grow your business, make money and be prosperous in China. That push is there in the people and in business and in government.

When you are pressured to succeed there's several ways to do it:
1) Copy the success of others to save steps
2) Make your products more cheaply and charge less for more sales
3) Make your products of higher quality and charge more for higher profits
... probably more ways too

If you look at those options. #1 is something China does very well, if a product is popular it gets copied often inferior to the original but often equally as good as the original. #2 is the other common technique and China has huge manufacturing capabilities so as a vendor you have lots of choice for cheap components and lots of competition driving you to make things even cheaper. #3 is an option North American and European companies often take but is harder for a Chinese company, English isn't as widely spoken in China but is very common in business outside China and #3 requires more time, more investment in marketing, more business connections and is just a tougher road to follow.

Option #3 is happening in China though, you just need to find good vendors. Think of it as how post-war Japan was. Japan was a synonym for cheap manufacturing for years but slowly transitioned and known for quality now. That will happen to a greater or lesser degree with China too, just give it time, China is a very old country but a very young economy on the world stage.

What I don't agree with is that some people feel china = junk, it's not the case. Cheap stuff = junk, we just happen to want to pay less and less and buy the junk which doesn't leave much room for the quality items regardless of where they are made. Just my 2 cents.

I also want to note, I've hired dozens of foreign workers over the years and in my experience all immigrants I've encountered are very hard workers, but the Chinese people I've had the pleasure to work with were tremendously hard working, very committed to doing excellent work, very respectful and just amazing people to know and be friends with.
Totally agree with the fact that the Chinese people (I have met) ,in general are nice people, I haven't done business with them so I can't say about reliability.
But the business atmosphere in China is another story.
We all know about their infringement on patents and bold face lies about the quality of many of their product.
BTW Not something I have ever heard about Japan, used to be cheap quality yes but then again they were only a few decades from being crushed in WW2.
China's economy, on the other hand is ranked 2nd in the world! Mostly due, in my opinion to dirt cheap labor and lots of it.
Still curious as to why China has such a tendency towards misrepresentation and stealing patented ideas.
 
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