48V 20AH battery for sale on ebay in USA any good?

[dogman dan]

Like many battery sellers on Ebay, it does look like they resell stuff. It's possible they email ping for support. But if you are looking for a bargain, and find one, it ships from the USA which is very good.

 

[auraslip]

I'm always surprised by the price disparity between cheap lifepo4 packs sold from companies on alibaba and the price of the battery we always recommend (ping). Like in lots of cases the price comes out to less than half the cost. It makes me think someone could make lots of money if they knew how to do proper QC, and had the cash to import enough to get a shipping break.

 

[dogman dan]

Yeah, LOT's of cash. Actually providing in country QC is pricy. Justin has wrote about it, how many battery suppliers did he try for nothing?

 

[Gordo]

One of the real problems with EVERYTHING from China is that the customer has always been the quality control. A specific problem with cells is they crank out 1000's per day and do a spot check every once in a while. If they find a bad batch, the manufacturer marks them as seconds and sells them off at a discount. We never know what we are getting, if we don't know the source. An additional problem, as evidenced by the power tool packs, is that even with tight QC, after a few cycles, one cell will crap out. Neither Dewalt, Makita nor anyone else wants this to happen. Cells that fail are just a fact that we have to accept. I think we have to stop flipping out and assume that everyone selling a battery is suspect. Personally, I am prepared to pay a little more from the seller (like PING) or Justin who has proven to back up what they sell. I bought my TS cells from a local supplier who offered me 12 months, local exchange. The price was only 10% more than the scam artists in Lacey, WA who took everyone's money and never shipped a single cell. It doesn't get any better than that. Looking for cheap anything is a recipe for disaster. Looking for a 1/2 price battery from an email address, is a very bad move IMHO. After reading battery posts on ES for months, I think that used cells from tool packs are more reliable than most others. The Prius stacks, although NiMH, seem to make a lot of people happy with the "bang for the buck."?

 

[www.recumbents.com]

Ha. The industrial park they list as their address is just down the road from where I work. I could drop in on them and see what they really have they if anyone is interested.

-Warren.

 

[CVillalobos]

After reading many posts and doing the numbers I just decided to go Lipo instead. I want to run 48V at 40Amps and that would take one big 2C battery. So I just bought 3 Zippy 6S1P 8000mAh 30C and a charger. One battery is for insurance.

 

[dogman dan]

Good idea for a 40 amp controller. If you want more speed later, a 48v controller can handle 14s. So you could add 2s packs later if you wish.

 

[Gordo]

Ha. The industrial park they list as their address is just down the road from where I work. I could drop in on them and see what they really have they if anyone is interested.

-Warren.

Did you take a look at their facility? Looks a little different than the artists conception.

 

[Gordo]

Your Google maps seems to show the same picture with the same vehicles in the parking stalls?

 

[Gordo]

Your Google maps seems to show the same picture with the same vehicles in the parking stalls?

This warehouse is different as your picture in Google
http://www.goasisenergy.com/

This picture is an artists conception, not a picture.

From the link you posted; http://maps.google.com/maps?ll=42.063739,-88.139507&spn=0.001462,0.004281&t=h&z=18&lci=com.panoramio.all,com.youtube.all,com.google.webcams

This is the picture we see;

Then we have the picture I posted from Google Earth;

 

[neptronix]

Gordo... love it

 

[Gordo]

I am always easily baffled by BS so I try to educate myself.

 

[www.recumbents.com]

Hi Guys,

I stopped by Golden Oasis New Energy Group, Inc. USA today at lunch time and spoke to "John". Yes, the facility in Hoffman Estates is just a warehouse in an industrial park. The picture on the web is their manufacturing facility in China, close to Hong Kong. The facility in Hoffman Estates is their distribution center. Their main business is stepper motors and controllers but they are now getting into the e-bike batteries and soon motors. He showed me the batteries and they are nicely packaged in blue shrink wrap. They had many 24, 36, and 48V batteries in several Ah ratings. The batteries are large form round cells like headway, and the pack includes a built in BMS. John did not know what I was talking about when I asked about the C rating, but he's just the distributor and is non-technical. He did however speak good English. The batteries come with nice looking chargers. The one for the 48V 20Ah unit was a 4A charger. He mentioned that he has sold many batteries and had no returns. I took several bad pictures with my cell phone that I will upload later.

-Warren.

 

[Ypedal]

awsome.. thanks for the feedback !!..

any clues on the BMS ?.. signlab or micro style mini bms's. ?

 

[www.recumbents.com]

Front door
View attachment 3
LiFeP04 Batteries of various voltages and AH ratings, plus boxes of batteries in the background. Yes, batteries are in stock.

48V 20Ah battery plus 4A charger

More batteries


No clue on the BMS. For some reason John did not want me to dissect the pack on the spot, and I didn't the spare hundreds to buy one for testing.

-Warren.

 

[dnmun]

kingpower charger, and the cells are 5Ah cylindricals.

you shoulda told him to come do show and tell on the sphere. he might learn something to help him sell packs.

 

[Gordo]

Warren;
Thanks for the response. Did you happen to ask if John handles the warranty or does a faulty pack have to first be shipped back to China at your expense? If he does not have any battery expertise, who in the company does? Now we are past the bullshit, maybe we have a new source of battery packs?

If John has a good command of English it is a little difficult to understand the misleading info on the webpage;
"Golden Oasis New Energy Group, Inc is a US-based company founded in April 2009 headquartered in Hoffman Estates, IL"

This; Is not quite THIS: And I would suggest MAY not be the best way to introduce oneself to ES?

 

[dnmun]

but that is the chinese factory drawing you showed, nothing to do with the US distributor.

in business, just because you sell someone's product does not mean you are the company that made them. i don't think anything has been misrepresented by him. it was nice for him to be courteous to warren too.

i do think it would help if he could expose the inner workings of the pack, maybe even for him to get a loose cell for capacity and Ri testing by the good doctor.

i have seen those cylindricals before. brent bolton uses them on his ecospeed mid drive.

it would help to know which BMS is inside too.

also he would find out here that he should have some spares and parts on hand for repairs when they eventually came back.

 

[joe tomten]

dnmun,

do you think the 5ahr cylindricals would be good for 1.5C?

Like 50v * 20amps out of a 15ah battery. Really probably 600-800 watts continuous is what I do out of an 16s 15ahr ping when commuting.

I have a couple of builds going for friends that I'm not comfortable setting up with Lipo, and it would be nice to have something stateside that of quasi-ping in performance quality, and a little cheaper to boot.

thanks,
Joe

 

[www.recumbents.com]

Note that these are pre-made packs. John is the importer/salesman.

I told him that he should note on the web that the picture was of the factory and he agreed to do that. He was very concerned that he get a good reputation and he knows how important that is for selling on the web. He noted that the factory he is using is one of four in China and that is one of the better ones. He's not set up for repairing the packs. I suspect he will just replace any that are returned while in warranty.

I'm taking donations to purchase one of these (48V 20Ah) to perform forensic surgery and testing to determine the C rate that the BMS will allow.
http://www.recumbents.com/donate.htm :lol:

-Warren.

 

[dnmun]

dnmun,

do you think the 5ahr cylindricals would be good for 1.5C?

Like 50v * 20amps out of a 15ah battery. Really probably 600-800 watts continuous is what I do out of an 16s 15ahr ping when commuting.

I have a couple of builds going for friends that I'm not comfortable setting up with Lipo, and it would be nice to have something stateside that of quasi-ping in performance quality, and a little cheaper to boot.

thanks,
Joe

this gets at what i wonder about with what makes a certain cell 5C and one on 1C. the way they are made is pretty simple, all of it is a layer of conductive copper coated with the carbon and the cathodic material and electrolyte and the separator, so what may be different?

they are made by rolling the sheets around each other in a spiral by what is called a 'jelly roll machine' that rolls it all into a cylindrical mass of these layers built around each other. the trick is the thickness of the conductive layers perhaps, but also how many layers are used and how many connections are made to the end plates.

the electrodes are connected on each end to the cap plug, which is underneath the part that looks like the top of the electrode to you. these connection are made by these small robotic spot welders that weld the little tabs on the ends of the electrodes that stick out from opposite ends for opposite electrodes and are welded to the cap on the underside in a spiral of layers of spot welded tabs covering the underside of the cap plug.

all this welding and rolling up of each layer as it is fed into the side of the jelly roll machine is done inside of a sealed cabinet, in fact all of this is done robotically inside sealed cabinets because the electrolyte, the electrodes, the cathodic material and the conductor itself are all easily oxidized and the lithium will suck water out of the atmosphere if any gets into the cabinets so they are purged with gases i am sure to prevent oxidation at any point. so after the jelly roll is made, it is then pushed into the plastic lined metal sleeve and the end caps are capped themselves by the plug you see, and then that is crimped around the perimeter and the head rolled over on top of the cap plug that makes the terminal. then goop added to seal the ends hermetically. all this is done basically in one operation, then the cell is racked as the goop cures and removed from the cabinet through air locks, to be tested at final test.

so the ability to get the current out could be a function of the surface area and the resistance of the flow of the ions through the electrolyte through the separator to the anode. so that is what likely is involved in creating the cylindrical and also the prismatic cells, the pouches are long single layers with just the two terminals of the electrodes, so the current has to flow a much longer distance through that conductive copper layer and in the process it looses a lot of energy i bet, so you cannot get the same amount of current for the volume and weight of cathodic material and electrodes and everything. so that may be why the pouches have the lower C ratings, but the cylindrical cells end up having the highest C ratings, because the distance the current has to travel out to the terminal is less, so less power lost, lower heating, lower Ri.

not sure how i got off on this tangent.

but to answer your question, i would expect that all of the cells made this way now, using commercial sources and qualities of the cathodic material, would be all using equivalent levels of equipment and manufacturing practices to protect the quality since they are in business. since all of the manufacturing problems in china have been learned and spread somewhat through the industry there, i would expect they all have fairly equivalent capacity to produce current. just one cell in the the doctor's infamous torture chamber would let us compare. or if there was some way for john to obtain an authentic discharge graph to allow us to compare it to the other known cylindricals. like the headway.


in short maybe 5C, but use 2C continuous as an estimate until you know better, to be safe.

i think you should try them, somebody gotta go first. post up pictures of the BMS.

 

[joe tomten]

For warrenty and other information I took a look at one of his ebay listings:
http://shop.ebay.com/kelinginc/m.html?_trksid=p4340.l2562

I now recall having seen these listings for some time now...

Want to try one. 2C max continous is all I need for my friends.

We'll see what happens.




Brand New 36V 20AH LiFePO4 Battery

for Electric Scooter, E Bike ( up to 800 Watt)

Free B.M.S / Free 4Amp Charger ( 4Amp charger Voltage 110V-220V )

12 Month Warranty


Specification from Factory:

Used up to 800 Watt

Voltage: 36 Volts

Capacity: 20 Amp Hours

Dimension: about 8.25 x 6.25 x 5.95 inches

Weight: about 16.65 lbs

Charging Voltage: < 45 Volts

Charging Current: < 5 Amps

Rated Discharging Amperage: 20 Amps

Max. Continuous Discharging Amperage: 40 Amps

Max. Discharging Current: 60 Amps

Lifecycle of the whole pack: >85% capacity after 1000 cycles.

Lifecycle of single cell: >85% capacity after 1500 cycles, >70% capacity after 3000 cycles.

 

[goasisenergy]

Note that these are pre-made packs. John is the importer/salesman.

I told him that he should note on the web that the picture was of the factory and he agreed to do that. He was very concerned that he get a good reputation and he knows how important that is for selling on the web. He noted that the factory he is using is one of four in China and that is one of the better ones. He's not set up for repairing the packs. I suspect he will just replace any that are returned while in warranty.

I'm taking donations to purchase one of these (48V 20Ah) to perform forensic surgery and testing to determine the C rate that the BMS will allow.
Donate to www.recumbents.com :lol:

-Warren.

Hi Warren
I removed the factory picture.I asked the factorty to take a picture. Pls give me a call

 

[joe tomten]

One is on it's way.

48v 15ahr

John sent me this photo of what the factory sez is a picture of the innards.

I'll do a review.

 

[jimw1960]

One is on it's way.

48v 15ahr

John sent me this photo of what the factory sez is a picture of the innards.

I'll do a review.

That picture shows a a 24p cell group with solid copper plate connecting the cells. Somehow I doubt that is what is being sold on ebay.