Eve MB31 Cells from Jenny Wu of Docan Technologies

[Xhumeka]

After watching @RayfromTX 's video on Eve MB30 / MB31 cells (video link HERE) I placed an order with Jenny Wu of Docan for 8 cells delivered from China to Toronto Canada, here is my review.

Order was placed with Jenny June 7th 2024 and the batteries were on my doorstep July 22nd - just 6 weeks, well under the 8 week estimated window!

Cells were packed 2 per box, with the boxes well labelled with "No Rolling" and "This Side Up" instructions:

The cells are protected very well inside the boxes, the foam inserts having proper cavities to protect the cell terminals. Each box contains 2 flexible busbars and 2 protective cell sleeves:

The last box also contained another baggie with 4 extra busbars and serrated nuts - a nice bonus!

Total cost (including shipping to Toronto Canada and Alibaba protections charges) was $783:

Overall the process with Jenny was seamless and I'm completely satisfied - she was quick to respond to my emails and answer any questions I had, and shipped the cells and provided tracking info within days of my order. Very happy with Jenny's service and I highly recommend! Thanks also to @RayfromTX for the video alerting me to this great deal, can't wait for your next vid Ray!!

 

[HRTKD]

I would argue that the packaging wasn't very good. Look at the underside of the foam "top" in picture #5. There appear to be indentations in the foam. Maybe the black plastic cap shown in the second to last picture was enough to protect the terminal stud. Given that the black plastic cap is poking through the clear plastic shrink wrap, it looks like the cap saw some stress.

Either way, that terminal type is pretty tough and I doubt there's a problem with it. Very good order to delivery time. I paid $76 each for 18 EVE LF280K cells, plus a 16s battery box and JK Inverter BMS. The shipping cost for all that was $321 ($17.83/cell, rolling all the shipping costs into the cells). I think I got a slightly better deal, but what it comes down to is if you're satisfied with what you got. I haven't compared the MB31 to the LF280K, other than really liking the terminals on the LF280K.

 

[Xhumeka]

I would argue that the packaging wasn't very good. Look at the underside of the foam "top" in picture #5. There appear to be indentations in the foam.

The cells are protected very well inside the boxes, the foam inserts having proper cavities to protect the cell terminals.

It might be hard to see from the picture, but you are referring to what I called "cavities" - the terminals did not make those holes, there is foam missing (cut out) to allow space for the terminals.

 

[HRTKD]

It might be hard to see from the picture, but you are referring to what I called "cavities" - the terminals did not make those holes, there is foam missing (cut out) to allow space for the terminals.

OK, if that's an actual cavity that was intentionally created, then it's pretty good packaging.

 

[740GLE]

USD $97/cell landed to your door, not terrible.

Have you done a capacity test? I wonder if these new MB31 test 340ah or such.

Your price is about what I paid for 280k ver 3 from Luyuan, back in mid May, but mine have dual threaded terminals.

 

[Alkaline]

USD $97/cell landed to your door, not terrible.

Have you done a capacity test? I wonder if these new MB31 test 340ah or such.

Your price is about what I paid for 280k ver 3 from Luyuan, back in mid May, but mine have dual threaded terminals.

I'm sure when you add sales tax and transaction fees it will be closer to $108.00/cell

18650 has these in stock for $105/cell with official EVE terminals. https://www.18650batterystore.com/products/eve-mb31-grade-a-cells-3-2v-lifepo4-314ah-battery

Ohh have the mighty have fallen, so funny now that Docan is trying to sell cells with legit qr codes they have had to jack up their prices.

 

[niktak11]

I'm sure when you add sales tax and transaction fees it will be closer to $108.00/cell

18650 has these in stock for $105/cell with official EVE terminals. https://www.18650batterystore.com/products/eve-mb31-grade-a-cells-3-2v-lifepo4-314ah-battery

Ohh have the mighty have fallen, so funny now that Docan is trying to sell cells with legit qr codes they have had to jack up their prices.

18650 sent me the fancy flexible tinned copper busbars with my order of MB31s too. A lot nicer than the plain flat aluminum ones they used to give out.

 

[Xhumeka]

I'm sure when you add sales tax and transaction fees it will be closer to $108.00/cell

The only transaction fee is the $16 Alibaba fee already included in the total I listed. I've also never been charged sales tax for orders from China.

I place these orders on my credit card, and I've never seen an unexpected or surprise charge appear. Duty fees are payed by shipper.

USD $97/cell landed to your door, not terrible.

Have you done a capacity test? I wonder if these new MB31 test 340ah or such.

Not yet... I'm hoping to have time to build this pack later this week, once it's done I'll post capacity results.

 

[Xhumeka]

Have you done a capacity test? I wonder if these new MB31 test 340ah or such.

I had a chance yesterday to start assembling the pack and testing the cells... I haven't done a FULL capacity test yet by completely top balancing each cell to 3.65 and installing a BMS, but I thought I'd post the results of my preliminary testing that I do with each pack I build.

For this test I use my trusted and true iCharger x8 Hobby Charger which does it's best to top balance to 3.60V and discharge to 2.6V, but since it's intended for a much smaller (ie 5 Ah) RC battery, it will never properly balance huge 300+ Ah cells, but at least it protects the pack while charging in series before a BMS is installed.



Do you like my "test bench" area?





I was a little curious to see how well these cells were "matched" based on the results my LiFePo4 QR code scanning app reported... I only scanned two, but the first two i picked seemed to be from different product lines/task orders:



I set my iCharger to cycle (charge/discharge/store) and went to bed for the night. When I got up this morning, the discharge process was still running. After 10.5 hours of discharging at 30amps, and just past the 314Ah (stated capacity) mark all cells were still discharging well and all above 3 volts with only a 38mV delta between all cells:



Just shy of 11 hours one of the cells hit 2.6V and the charger started dropping amps until it reported the battery discharged:



So I got 328Ah out of this pack, but I have no doubt after properly top balancing each cell to 3.65 and discharging to 2.5V I would see mid to high 330s. I'll post final tests once I finish this pack 100 percent, but happy with inital tests!

 

[740GLE]

nice wood stove

My in-laws have one very similar, a Jotul combifire 4 (Easter island), that has to be a sister to that unit.

 

[BuffaloTrace]

I've found there are a lot less good options for 24v compared to 12v and 48v.

 

[HRTKD]

I've found there are a lot less good options for 24v compared to 12v and 48v.

I'm in the middle of a 48v build and I think there's more options for 24v, especially when it comes to fuses and breakers.

 

[BuffaloTrace]

I'm in the middle of a 48v build and I think there's more options for 24v, especially when it comes to fuses and breakers.

Aaah yes I meant to say there aren't a lot of "pre built" options to the OPs 24v diy build. Commendations! Nice to see the diy builds on here.

 

[Luk88]

Have you done a capacity test? I wonder if these new MB31 test 340ah or such.

I have a spreadsheet of 50k of these cells tested (as well as I tested 4 from my order) and they are mostly 330AH. Still pretty good in my book! (As long as you get real ones).

I'm sure when you add sales tax and transaction fees it will be closer to $108.00/cell

18650 has these in stock for $105/cell with official EVE terminals. https://www.18650batterystore.com/products/eve-mb31-grade-a-cells-3-2v-lifepo4-314ah-battery

Ohh have the mighty have fallen, so funny now that Docan is trying to sell cells with legit qr codes they have had to jack up their prices.

Hmm, have they ever sold them cheaper than ~$70? I'm not sure you can compare on price by including shipping and taxes.

Also this is the first time I see them packed 2 in a box. I got 4 in a box from QSO, but that was shipped within the same country.

Edit: I just placed another order with my supplier and interestingly they are all sold out here in Europe (I have to wait 4 weeks for restocking, normally I'd get it overnight). The price was $79 delivered, but as I was placing my order I noticed their prices from China werehouse are in the $65 range... So not far from the $70 the OP paid.

 

[Alkaline]

Docan is also selling these frauds:

https://diysolarforum.com/threads/missing-hithium-qr-codes.85418/#post-1116638/

So it all depends on who you are, if you are one of there fans bois/pumpers you'll probably get cells with real qr codes, if you are schmuck you'll be like that guy. BTW this is still happening in June 2024 so Docan is very much still in the scamming business.

I'm not going to get intot he grade A vs B debate because based on my own tests grade B is very viable assuming its not a trash grade B cell. However, does not change the fact the Docan entire operation is based on lying to customers claiming grade A cells when in fact shipping them grade B and there are plenty of threads like the above to support this.

 

[Xhumeka]

Docan is also selling these frauds:

https://diysolarforum.com/threads/missing-hithium-qr-codes.85418/#post-1116638/

One of the last posts (by the OP) in that thread you linked says:

After top balancing and capacity checking as 12v packs I can confirm that they are performing above rated AH.

Each pack has given between 293 and 298AH. They are using JK-B2A8S20P BMS's. I spent time to fully balance and then discharge/recharge twice and capacity checked each discharge.

I wrote to Jenny apologising for my earlier accusations portraying her and Docan to be bad actors.

I wish now to say to forum members that Docan and Jenny Wu supplied me exactly what I paid for and can be relied upon to be honest and above board.
It's against forum rules to post the contact details but a Google search will find them

Thanks

You may call it a "fraud" but the guy who bought them seemed quite pleased....

 

[Alkaline]

I was also very pleased with the $300.00 Rolex I bought in Dubai it shows the time just fine, but its not a Rolex... @Xhumeka would you like me to post links to people who have NOT been pleased with Docan? I don't think you will like the direction this thread will go...

 

[Luk88]

Sadly this field is full if fraud. Even if you manage to get good cells from one seller it is by no means a guarantee the next batch will not be a scam. The fact the guy from the Hithium thread is happy doesn't change the fact QR codes were faked. Who knows if his cells last half the time they otherwise would.

If you want to know for sure you do what I did here https://diysolarforum.com/threads/checking-out-some-new-qso-cells-i-received.86551/

 

[bds70]

Docan is also selling these frauds:

https://diysolarforum.com/threads/missing-hithium-qr-codes.85418/#post-1116638/

So it all depends on who you are, if you are one of there fans bois/pumpers you'll probably get cells with real qr codes, if you are schmuck you'll be like that guy. BTW this is still happening in June 2024 so Docan is very much still in the scamming business.

I'm not going to get intot he grade A vs B debate because based on my own tests grade B is very viable assuming its not a trash grade B cell. However, does not change the fact the Docan entire operation is based on lying to customers claiming grade A cells when in fact shipping them grade B and there are plenty of threads like the above to support this.

I can tell you sir, I am no schmuck. A cell is not "good" because it has a QR code. It's "good" because it performs well and within or above its stated capacity.
Perhaps before writing such judgemental posts, you might have read through the entire thread, then you would have seen that every one of the 16 cells capacity tested above its rated 280AH. They are now in operation and performance is above my expectations.

So maybe you can refine your comments to reflect the reality of the whole thread, and the sister thread that I made clear I was incorrect in my initial thoughts.

Have a great day.

 

[740GLE]

My concern isn’t how they test day one, but how they age over the next year or 5. That and capacity should also be followed up with a voltage drop test.

 

[bds70]

My concern isn’t how they test day one, but how they age over the next year or 5. That and capacity should also be followed up with a voltage drop test.

Well I guess we shall have to wait until 2029 for my performance report on them then.

 

[bds70]

Sadly this field is full if fraud. Even if you manage to get good cells from one seller it is by no means a guarantee the next batch will not be a scam. The fact the guy from the Hithium thread is happy doesn't change the fact QR codes were faked. Who knows if his cells last half the time they otherwise would.

If you want to know for sure you do what I did here https://diysolarforum.com/threads/checking-out-some-new-qso-cells-i-received.86551/

And how do you come by the proof that the codes on my cells were faked? There is no proof of that at all.

 

[Luk88]

And how do you come by the proof that the codes on my cells were faked? There is no proof of that at all.

Two things, the first being a lot more important than the other:
- background of the QR code has visibly different shade than the surrounding area and visible scanlines. This is not how these codee look when genuine. It looks sanded/polished then relasered using a raster image. If you see every other QR code on another cell you'll see the background is pristine (not just around the code, but between individual fields). This is a sign it was lasered as a vector image with empty background.
- The code doesn't read. Not just the manufacturer field, but the date production line etc. The code is a Chinese standard so it can't just be a case of a manufacturer doing their own thing.

Now @bds70 this is not meant as an attack on you. Readers of this forum know I've been scammed too and probably most of others that buy cells. We're just trying to get to the bottom of things, which cell sellers are scammers and which aren't. By the information I found it seems up until maybe a year ago there was no real grade A cells to be had from any Chinese seller and all that said "grade A" knew very well they aren't. This has changed at least here in Europe for me(I did get real grade A in a number of orders, well see about my next one), but why and for how long? Who knows?

 

[Alkaline]

I can tell you sir, I am no schmuck.

You are right, a schmuck would have realized when presented with the evidence they have been had, clearly that is not you.

 

[bds70]

You are right, a schmuck would have realized when presented with the evidence they have been had, clearly that is not you.

Such a nice person. Glad I am not in your mind.