* * * Group Battery Purchase * * * | Endless Sphere DIY EV Forum

Group Battery Purchase

We are getting to a point where LiFePO4 prices are coming down and our collective desire is going up. By using the power of collective bargaining we should be able to find some way to create a "Group Battery Purchase" where we can get the price down because of volume.

Let me first apologize in advance for the people here that make battery building and selling a business. The people who would likely go in on a group purchase are those that post here regularly and are very knowledgable about all aspects of this technology. The "public" will need to buy pre-configured battery packs, but many of us here are nearly manufacturers ourselves in our depth of research and knowledge. So what we are doing is not for the "common man".



Patrick has presented an ability to deliver these LiFePO4 Cylindrical Cells () under the condition that a bulk purchase of 100 can be done at a price of $30 each.

Capacity: 10Ah
Volt: 3.3v
Dimension(mm): 40*138mm
Weight(g): 400
Standard Discharging: 1.0C
Quick Discharging: 3.0C
Max Discharging: 10.0C
Cycle Life: >Times
Temperature(Discharge): -20~75
Storage Temperature: 0~45
Self-Discharge (Month): <5%
Energy Density wh/L: 170
Energy Density wh/Kg: 80
Initial Internal Impedance<6m

http://www.made-in-china.com/showroom/yesa001/product-detaildqSmjwhOPfco/China-LiFePO4-Cylindrical-Cell--.html

I notice on this link that they say the minimum to order direct from China is 10 pieces, but they don't say the price.

A Two Stage Process

As I see it there is a two stage process that needs to take place:

First... it's necessary that collectively we identify the absolutely best deal that can be found. If the best deal is through Patrick then that's great and we can go forward. If another deal is found that might have counter balancing conditions (like a very high volume restriction) then we collectively need to cross that bridge when we get there.

Second..., once the best deal is found, if a number of people are required to make up a high volume order we need to get first a pledge of interest and later that needs to be followed with some more concrete $$$ to prove that this is going to happen. We might want to require an advance of 10% of the purchase price so if someone backs out the remaining cells can be turned around without anyone feeling hurt. (other than the person that backed out, but that's their problem) The other option is to somehow make the money transfer done collectively all at once... I'm not sure how that might be done, but if Patrick was involved he could probably use his business to do the accounting side of it.

Feel free to comment on any aspect of this process or present a deal that you might have found... Wow, That is one sweet deal at a very desireable time

:? However, Yesa sells these at $35 each (month ago) without buying 100 at a time. Also, we were told by a US seller that some of these from China are seconds that didn't make the grade and are almost a year old, this is why there is no MFG date markings on the ouside cover. I don't know how much of this is true, or these particular cells either. BUT... Shipping from China alone is $180 for 32 cells.
I'm all for saving money and definately buying 32 of these wonderfully designed cells in a month. But still leaning towards buying from our local North American brothers (who post here)... for a few reasons.
a) We save $$$ on shipping charges
b) We support our countrymen and have closer ties if we have any problems.
c) And lastly, I worked in manufacturing for many years, don't get fooled by appearance, It costs more to make a quality item, and get them independently tested like our local boys did. It's late, hope this makes sense tomorrow morning.

P.S. I think these cells should'nt cost more than $30 though, heck, street drugs are cheaper than that, so i'm told PingBattery,

I represent a group of people who are very dedicated to electric vehicles and are searching for a dependable and affordable supplier of LiFePO4 battery packs. Our group has an online website where products are discussed. We would like you to register with us and "sell" your product through us. We can give you additional credibility with the electric vehicle crowd because we have some really smarts guys in our group.

http://endless-sphere.com/forums/viewtopic.php?f=14&t=

My name is "safe" online

There seems to be no response, so that makes me suspect that they are either too busy (or already on their chinese vacation) or they are not interested in selling themselves to an educated audience. I'm sure there's no shortage of people who will buy anything they post on ebay so they might not need to bother even trying to sell. We will see.

It would be nice to get a relationship set up with people who do live in China and can get the raw batteries at "chinese" prices. However, the shipping is rather expensive so when you do the final calculation the "original price" and the "final delivered price" are quite different. My guess is that in China the cells go for maybe about $15 - $20 each and all the rest is shipping and markup. It would be nice to know more... Hey everybody,

I thought I'd chime in here, and let you know how things stand as I see them.

First, the cells are 10C rated, 12C max as I understand it it. 3C charge is correct.

Second, I talked to the powers that be, and we can do $30/cell with a minimum 30 cell order. $35/cell is to cut down on onesy-twosy orders, which are a pain, almost more trouble than they're worth. Hopefully this will also eliminate the logistic trouble of coordinating the buy, the money, etc.

Third, we don't have a huge number of cells yet; we've got a few test packs and some loose. If any are going to be ordered, it should be this week, as we're going to be out of pocket for the next two weeks. It was said earlier that Chinese New Year is almost upon us, and this may delay things, I don't know. At least you know we're not sitting on some old inventory.

Fourth, I am expecting about 3 weeks shipping time to San Francisco (leaving any complication of the New Year aside). Frankly, I expect it faster, but would rather give an outside quote than disappoint people.

Fifth, there is the issue of testing. We can certainly put some on a CBA and give discharge curves. I can also send one to somebody on the board for independent analysis. My thought was DoctorBass if he is amenable, but I am open to suggestion. Fechter works in the neighborhood, and I could just drop one off to him - much faster if he has the time.

Lastly, what I am expecting in response. What I am looking for is a sense of commitment. If you want delivery in the next 30-45 days, you need to speak up and state your interest (you can certainly PM me, that might be more comfortable for everyone), so that we can get an idea of what to do. Let's say Tuesday (midnight PST) cutoff. No deposit required - it's the honor system. Remember the honor system works both ways - if you are unrealistic that might affect any future dealings. You can state this in any way you want:
I definitely want xx cells!
Think I want yy cells, but want to see the test results.
I'm sort of interested in zz cells, but not really sure . .

Obviously, the more commitment, the higher priority for your order. I can't say fairer than that.

Have a great weekend!

Patrick

Patrick said: ...we can do $30/cell with a minimum 30 cell order.

I could use the full 30 and make two bikes with them, but would rather start small if possible. 15 is all I would need (in series) to produce a 48 volt pack that should be able to pull (4C) 40 amps pretty easily. That's $450 for a 48v 10ah (480 Wh) pack.

Anyone out there interested in 15 so that you could split it with me?

This is half of the price of LifeBatt.com for the same cells. ($440 for 8 compared to $450 for 15)

However, I still have to ask if there is a big hurry. It's only the beginning of February and most of us won't be actually using our bikes until about May or June. The weather in the midwest really sucks, my garage is still in the 40 degree range, so I won't be working on anything for a while.

I just have this feeling that if I buy something now that a few months later the price will drop. It's like buying a flat panel tv a few years ago... everything was $. Now you can get the same product for about $700, so I'd rather buy the minimum amount that I need for now and not any more. Yes, the cells are threaded (have bolts) on each end. Red on one end, black on the other. I will post a few pictures later (in the middle of cooking, another joy in life, the BBQ timer is beeping). Also have some codes (and presumably serial numbers) on each.

They are not made in Shenzen (China), but in Taiwan.

Also, I agree with Safe. LiFePO4 is exploding, and (although not literally) I mean that in both a good and bad way. Yes, always something better "just around the corner". Myself, I still use lead - I've got so much (maybe 10 kWh) who cares? But how far away that corner is is a personal question. If you are happy with what you've got - stay with it!

However, his example was years compared with months. It may take a month or two just to get these. I'm not pushing it, just trying to offer an alternative to earlier adopters. http://visforvoltage.org/forum/-hands-test-48-volt-20-ah-lifepo4-pack-ping-battery

Re: Hands on Test : 48 Volt 20 AH LiFePO4 pack from Ping Battery

Submitted by andys on Thu, 01/17/ - 02:23.
In answer to the question above, I also own a YESA 48v 12AH pack that cost more than the 48/20 does from Ping. Pings pack has way more power and capacity in my experience with them both on the same scooter, and of course it should being a 48/20. So far, its a way better deal. I didn't ask too much detailed info on what individual cells he used. He mentioned something about them being a "soft as opposed to a hard style" that YESA uses. The cells he uses are also more compact. YESA's 48/20 wouldn't fit in my battery box.

The "soft" cells are what is called "prismatic cells". They are like a foil pouch so you can pack more of them in a tighter space.

Don Harmon

So PingBattery is using some odd LiFePO4 cells, not the cells.

Hello Peter,I am a bit late to answer, but after reading a lot on Will Prowse's forum. I ended up buying my cells from Shenshen Basen https://basen.en.alibaba.com/  They are a little cheaper than your vendor.  On my first order of 8 280Ah cells, one of the boxes was dropped and one of the cells was damaged despite being well packaged.  The cells look good, no bloating etc and the pack worked out fine at first, but after a couple of weeks, the cell started to drop in voltage a lot faster then the others.  After going back and forth with the vendor for a few weeks, they send a replacement, which should arrive in a few weeks I hope.  Right now I am only getting 50% of the capacity because of that single cell.   They seem to be one of the better vendors on Alibaba, although still not quite as good as what you would expect from a European store.  Shipping takes about 2 months to Canada.  I will be interested to see your experience with this vendor.
On the boating forums, they seem to recommend smaller cells, 100Ah max because the bigger ones 280Ah might sustain internal mechanical failures with the constant bouncing.  However, you will have to do some more research on that as I can't verify that claim, but you might consider some form of cushioning.

As for the SBMS0 and DSSR20's, I chose those because they produce almost no heat, heat is wasted energy most of the time and that heat has to be moved using even more energy.  The second part is the SBMS0 uses a signal to switch of the inverter charger, in my case a Victron Multiplus as I want to be able to use shore power/small generator to charge my battery.

All in all it has been a steep learning curve.  The short circuit current these cells are able to produce are frighting.  Be REALLY careful!!! Insulate your tools and cover the terminals when you do the install and use circuit breakers.As for balancing it took me forever, wire them in parallel first for a day or so, then wire them in series, let the solar charge the battery and trust that the BMS0 (properly wired and configured for LiFePo4) cut of the charge.  After that, assuming they are not too far out of balance, (I do not know the exact figures, but you do not want high currents) wire them back in parallel and top balance using a bench top power supply.  A better option might be the EBC-A20 or if you don't want rewire from parallel to series twice  it's bigger brother, both available on Aliexpress.   After top balancing install the batteries in series (again) and do a partial discharge to 80% of capacity.  Top balancing takes patience and relying on the equipment to turn off when it is supposed to, helps.
Guys, thank you for your responses!
JHon,I was in direct contact with Basen, for 24x 310Ah LiFePo4 they wanted $ including shipping and taxes to Czech rep.These sellers on Aliexpress offered me best price $ - $:I have picked LiitokalaVariCoreFlagship Store for these reasons: almost best price, fast English communication, Will Prowse tested theirs 280 Ah cells and they look fine. I will let you guys here know if this pick was lucky.Bouncing problem.It came to my mind few times but in the end I was just going to risk it without cushioning.Can you imagine cushioning real solution in the van of 135 kg block of cells? I will probably compress them just to have one single piece. But I guess primarily I need to mount it securely to the van. Would someone have a suggestion how to securely cushion such battery?
Yes, the short circuit current keeps also bothering me. Impedance of single cell is according to datasheet only 0.18 mΩ. That is crazy.
What is short circuit current of 8S3P pack? Over million amps? If I will be even able to get a fuse which will be able to break such current..Does even exist circuit breakers what can stop such current?I have sent a question to Basen what would be short circuit current of 8S3P battery, I am looking forward to their reply.
Dacian,why do you think their bus bars are useless? I imagine they are quite thin.. but I will take only 150A, they could handle that. Maybe their lower quality bus bars would help me to lower short circuit current so fuses or breakers could be more successful. Does it make any sense?
Dne úterý 1. června  v 19:00:54 UTC+2 uživatel napsal:
Hi,I also ordered 24 310Ah cells but on Alibaba - from Shenzhen Beiersite E-Business Limited in middle of March 21. Got cells delivered in Juni.Cells were thoroughly packed in foamed boxes to 4 cells. On checking the cells I found one cell sitting at 2.99V, all other cells were on 3.29V. One cell was damaged on one corner as it was dropped.I filed a dispute after trying to negotiate with the seller. He claimed that all cells were tested before shipping, so it muss happened during transport...In the dispute the seller suggested that he will send new cells if I agree and close the dispute. I did and was looking forward to get new cells. Instead of shipping new cells the seller refunded those two cells straight away! I was not happy and tried to escalate this face solution of the seller to Alibaba in opening another dispute - but Alibaba didn't reply. My second dispute was not even filed! The seller replied that he had refunded the cells and he would have send new cells only if I had placed another order!Meanwhile I assembled the battery - same as Peter 3P8S and it turned out, that the 2.99V cell is playing crazy within a cluster of 3 cells.On charging this cluster reached OVD first and drops fast in voltage after a short time without any loads on the battery!Prior, I had all cells assembled to a 24V system and charged with my victron MP 2 with SBMS0 as controller. Then I re-arranged cells in parallel and toped all up to 3.6V, left its for 24h in parallel and reconnected the cells in 3P8S configuration.Observing the SOC/voltage of the battery/cells I'm pretty sure that this block will not deliver the performance intended/ordered/expected.Finally, I ended up ordering additional 4 cells from the same seller to get same brand of cells to swap cells which are not performing.I'm very unhappy with this deal - next time I will consider buying Winston cells instead of this Chinese crap.I posted this story already on FB and was blamed for can going for the cheapest cells - it is well known that these cells are not A-Grad...offer was for A-Grade cells...To justify my purchase, I was not going for the cheapest cells on Ali, but for the most comprehensive deal. No tax no duties would come on top, only shipping - that was my criteria.What I have learned from this deal - next time - if ever! - I will order more cells than needed. An additional set of four cells should? be enough  to assemble the desired system. After completion of the project I will sell these surplus cells for a reduced rate - unveiling the background/history. So I could reduce my loss...Peter - I attached some pictures of my battery box, made out of 24mm plywood. Compression is achieved/maintained with stainless steel threaded rod. With a router I cut a 9mm groove in the plywood and inserted a sheet of 9mm plywood where cells are resting on. The bottom set of rods is right underneath this floor inserted to carry the weight of the cells. To secure the box on the floor I screwed  aluminium angle profil into the wooden floor in the distance of the box, inserted the box in between and drilled holes through the box walls. The floor where the cells rest on is prox. 50mm from the bottom. From the inside I put metal inserts in to be able to fasten the box to the angle profil...Cells I wrapped in insulation paper - Dupont Nomex paper, pricy, but I wanna to be safe... Box is approx. x265 footprint, hight is 360mm...calculate 50mm floor, floor, cell hight plus an additional 30 to 50mm for bars, cables and rods.As it was mentioned earlier, delivered busbars are somehow useless. Holes only fit if one puts cell flat next to each other, won't fit if in series. I made busbars from copper flat material, 20x3mm equals 60mm2. I'm also not drawing more then 150A with my MP2 24//70.I'm not happy with the busbars as its are rigid allowing no length compensation on temperature differences.With this amount of capacity - once updated with new cells! - I'm hoping to cycle the battery only within 30 to 80% max - though giving hopefully a long lifetime...My application is also RV. A word to the fuse - I fitted a T-class fuse from Blue Systems, 400A. It'll safely disconnect the battery from the RV in worst case. AC I'll get from my victron MP2 and hopefully disconnects by order of SBMS0 and DC loads are cut off via a victron BP. Since I only run small appliances like LED light, Truma gas heater and fridge, a 65A BP will do the job.A suggestion to make life with SBMS0 easier - I bought cat5 lead and cut off one plug, jammed the individual cables into the green connector and mounted a socket for RS45  behind the wall and connected the individual cables to inverter, shunt, DSSR20 and BP. With this setup I only need to unplug the cable from the socket! Easy...FrankI used EBC-A20 to top up cluster 7...@Peter,This 310Ah cell will likely end up with 280Ah-290Ah capacity.I've seen other people's experiences in other forum threads.For your reference. Of course the final result is based on your test.@Dacian,Your mention of the weight of this 310Ah cell reminded me that this could be another piece of evidence. Because the weight of the A gauge EVE 3.2V 280Ah cell I sell is 5.3kg (+-0.3). This would be a quick judgment of the battery capacity.@Frank,Your system looks great. I'm sorry to hear about your unpleasant experience with other Chinese sellers. I'm a Chinese seller, but I only sell A-grade EVE 3.2V 280Ah cells, model LF280N. If you need this cell next time, please contact me.@da... @svsoggypaws.com,I'd like to continue your conversation and explain the price of A-grade cells. Because I found that most buyers are not very knowledgeable about the price of the cells, after all, you can see all kinds of prices on Alibaba.In fact, the three brands that we all know, EVE, LISHEN, CATL, are relatively close in price for the same capacity of the cells. So I take EVE 3.2V 280Ah as an example, the current price of this cell without shipping costs, A gauge should be $115-$125. The reason for this range is that each seller has different operating costs and profit targets. Some sellers may lower the price of the cells to attract customers, but you will find that they raise the shipping costs. The final price is still relatively close.About six months ago, the price of A gauge was $90-$100, but due to rising material prices and a big shortage in April-May, the price of cells (including the factory price) went into an upward spiral until today. The price has gone up about 20-30%. Material prices haven't started to come down yet, so cell prices will probably stay at this level for a while.So for a 280Ah, it's hard to get a Class A product under $110 today. If you see a price like $9x, make sure you look at it with shipping costs, if the shipping costs are normal or lower, then it's not an A-grade cell.I'm not familar with other small brands of cells, so I can't explain their prices. I was curious about their prices and quality. So I've been tracking about their situation in use.
Tim LeeHi Dacian,The definition of B grade products is actually very simple from the factory end, one or more of the tests do not meet the requirements of the product but close to the test standard is B grade products. Some B-grade products just can not meet the requirements of the appearance, such as pits, scratches, terminal size deviation, but this does not affect the function, completely can be used as A-grade products.Some B-grade products are not in line with the standard parameters, such as capacity slightly lower than the standard, or resistance slightly higher than the spec. These products can be used in the field of parameters and consistency is not very high requirements.So B-grade is not quality reject. It is accepted by lower standards. It is not used, it's brand new.In actual production, there are not a lot of B-grade products produced. So why does it seem like there are a lot of B-grade products? Since enterprise level customers generally only use A-grade products, B-grade products are more often used in the bulk market. There are some areas where the standards are not as strict, then purchasing B-grade products can ensure functionality and cost savings.Another reason may be unknown to buyers yet, sellers selling A-grade products are less profitable (based on market competition and the price transparency of A-grade products) and prefer to sell B-grade products for high profits(bad money drives out good).In fact, for individual users, it is the best value for money to buy B-grade battery cells. But it may also be more expensive. Because the definition of B-grade in the market is complex, not all B-grade we see is "real" B-grade (as the define by factory side). The price of the real B-grade is not as low as we think, as the performance is close to A-grade, so the price of B-grade is always not far from the price of A-grade. This complexity is the root of the variety of prices we see today, used/refurbished/fake/old stock, etc. are also said by some sellers to be B-grade products.If can find a seller which supply real B-grade, it is a good way to save money. But for most buyers only buy 1 or 2 times cells in the 3-5 years, it is not easy.Hi Peter,You are right, it has only 240Ah capacity (I thought it could be up to 280Ah according other thread I saw).The original QR code indicates that this is a 3.2V 230Ah battery cell from REPT. This can be read from the markings (REPT 3.2V 736Wh). REPT stands for REPT Energy Co., Ltd. which is a Chinese battery company that develops and manufactures power LFP and ternary lithium batteries. Most people may not know about this company, so I'll explain a little more:Although it is a relatively new company, founded in , the founding team has been developing LFP batteries since ). The company is growing fast. It mainly supplies power cells to electric vehicle companies. So it is not common in the wholesale market.Last year () it entered for the first time the market share ranking of EV power batteries (Chinese market) and was ranked 8th. EVE ranked seventh and LISHEN ninth. (Top 10 list: 1, CATL; 2, BYD; 3, LG; 4, CALB; 5, Gotion; 6, Panasonic; 7, EVE; 8, REPT; 9, Lishen; 10, Farasis)It ranks fourth and EVE ranks fifth in the market share of electric vehicle LFP power batteries (China market). (Top 10 list: 1, CATL; 2, BYD; 3, Gotion; 4, REPT; 5, EVE; 6, Lishen; 7, GreatPower; 8, Wanxiang123(A123); 9, CALB, 9, Lishen, 10, Anchi)I don't know the serial number coding rules of REPT. From the length of the serial number "08ICBA9A", it looks a bit like EVE's serial number rules. According to EVE's coding rules as you said 08I is the manufacturer, 9A6 is the date, representing the product is produced on October 6, .But since we already know it is a REPT 230Ah LFP battery cell. The interpretation of the serial number is not important.So there are at least two conclusions that can be drawn now: 1, they are fake 310Ah battery cells; 2, the original cells are not A Grade REPT 230Ah cells.In all rest cases, the best case that I can think is they are B grade REPT 230Ah cell. Thus at least you can still use them in future.