3.2v 500ah lifepo4 batteries

I'm seeing these batteries on Amazon, etc.  It seems like they come from China.



It seems like, if you're really thrifty, you can get 16 for under 2000 USD.  If my math servers, that's 25.6 kwh of storage not a lot of money, relatively speaking.  Has battery storage really gotten this much cheaper in the last 24 months?

So far I haven't found any testimonials, so I figured I'd ask if anyone's heard anything about them.

I'm looking for a battery bank to pair with a Sol Ark 12K.

I know absolutely nothing about this specific product and offering, however I have been looking in to 18650 cells for ebike batteries. The groups I am a member of have been discussing a lot of fake batteries being offered for sale from China; ones that claim Ah ratings that are far beyond what is possible with current battery technology, and at prices that are unrealistically low.

I'm not saying that this is the case here, but definitely do your homework before buying.

Michael Cox wrote:I know absolutely nothing about this specific product and offering, however I have been looking in to 18650 cells for ebike batteries. The groups I am a member of have been discussing a lot of fake batteries being offered for sale from China...

Michael,
It seems like prices of less than $100 / kw are not unheard of these days, but on this scale I'd expect to pay a bit more.

(Having said that, most if the places with the best prices are out if stock right now, so they may in fact be a bit more.)

By comparison, how much are you paying per kwh with 18650s these days?

Not sure how it works out but you can expect to pay between £2.50 and £4.00 for a name brand cell of good quality.

The issue we were see was they were advertising products that were twice or more energy dense than any known lithium battery technology. That product simply cannot exist, so the price isn't really relevant.

If they are 3.7v and 2.5ah for 4 Euros, that's actually quite a bit more than I'd expect; over 400 Euros per kwh.  You can get an LG power wall, which includes a charge controller, etc, for less.

While I'm seeing that 2.5ah is common for 18650s, I'm guessing you're quoting higher capacity cells.

I don't think you will get new cells that passed quality control.
So either they are old ones (that does not mean they don't work) or something was off (which also does not mean they don't work).

I would inquire about the origin and get a written response that verifies the number of cells and their capacity and that you can return them (at their cost?) if the capacity is not reached.

The price is about 25% of what I would expect.

Believe nothing from China until it is tested.

They often sell grade B cells and do not match the advertised amp hours.

If a pack was built with these  4s,   4p  with 16 cells

12.8 V         2000 amp hour

12.8 * 2000   / 1000 =

25.6  KWH

But that is very very hard for me to believe,   I would look on youtube,  and check reviews to make sure the info is correct.

YouTubers say you can get lithium cheaper than lead acid these days, but they are hit and miss.  If you want to go that route, I would watch the YouTube reviews and follow their links to specific products.  

Brian Church wrote:If they are 3.7v and 2.5ah for 4 Euros, that's actually quite a bit more than I'd expect; over 400 Euros per kwh.  You can get an LG power wall, which includes a charge controller, etc, for less.

While I'm seeing that 2.5ah is common for 18650s, I'm guessing you're quoting higher capacity cells.

The batteries for ebikes are high spec - High Ah, high max current draw, very low internal resistance. Weight is at a premium on a bike and converts directly to useable range.

R Scott wrote:YouTubers say you can get lithium cheaper than lead acid these days, but they are hit and miss.  If you want to go that route, I would watch the YouTube reviews and follow their links to specific products.  anything.

Speaking of:

One youtuber who seems to know his stuff reviewed some 3.2v 100ah lifepo4 sinopoly batteries, and found then to be quite good, despite being the cheapest on alibaba.com.

It was from the link in the description that I found the 500 ah batteries from the same seller.  Then I saw the batteries popping up everywhere.

Obviously, I can't extrapolate the youtuber's results to other batteries, so the purpose of the thread is to see if anyone had heard anything.

I have quite a bit of experience with lithium batteries, including owning my own lithium battery company.  All companies, whether in the States or elsewhere, buy their cells and BMS boards and components from China.  That is just the way it is.  So you can obviously get really high quality products from there and really cheap, gimmicky products, too.  That is why several people have stated that you have to test first and that many Youtubers have mixed results.

The adage that you get what you pay for applies here.  Even the worst lithium cells will outlast all but the best lead acid cells and outperform them.  That comparison is fairly easy to make on a performance and life cycle level.  Cost in the long run is debatable and one I get into quite frequently with people who are either really for or really against one or the other (I defend both types).  But the problems come when you try to compare lithium to other lithium batteries.  There are numerous Lithium Ion chemistries, including LFP or LiFePO4, and they are all different.  Then you have Grade A cells and Grade B cells and other grades.  And there are no standardized methods for testing.  Some companies charge and discharge on a 1C rate while others may use a 0.5 or 0.333C rate.

So like I said, just go with the get what you pay for theme and do the best you can.  Ask questions and if you don't get answers move on.  I try to be completely transparent and open with all the data on my batteries including how they are tested and where they are made so that people can make an informed decision.

It could be that we are at a (pretty good) crossroads with LiFePO4, in terms of finally moving off of Flooded Lead Acid (FLA) batteries (which are maintenance-intensive, heavy, and problematic).

We can:

 - build our own LiFePO4 battery bank - if this describes your capability, then everything stated above in this thread applies. My gut feel is that we are at the 280Ah to 300Ah range of quality cells. In this range, everyone is DIY and having good results. I have plans to build my future "big bank of batteries" with this route, but it is literally the "slow boat from China" method. It will take me months to years to get this done ... picking cells, picking the BMS board, ensuring everything plays well together *and* gets me what I want (big Ah's, software management capabilities, etc.)

 - buy our own LiFePO4 batteries, from fairly reputable vendors - I jumpstarted several projects at once with this method. I purchased two 100Ah batteries from SOK, to enable several "mobile" projects around the homestead. I purchased two 300Ah batteries from Ampere Time, to replace my aging and problematic FLA battery bank. I've had great success with both. If this describes your more immediate need, then it is ready now.

The point is, it's a good time to go whichever route works for you, or in my case, both, which will work for me.

It does look like they are from China.
So the carbon costs are astronomical compared with local to your own country.  
But if it is all you can afford, there are a thousand other ways you are lowering your foot print.

Do the best you can and give yourself a break you can't do it all.