At this point... if you are buying From Alibaba/Aliexpress you deserve what you get.

[Just John]

EBC-A40L High Current Lithium Power Battery Capacity Tester

The Youtube Channel off-grid garage has been using this fine piece of equipment and had my itchy online shopping finger ready to say:"buy it now". It has a high capacity but is limited to 5V cell voltage.

Measurement Tools and Analysers

UNI-T UT210D True RMS AC/DC Current Voltage Mini Digital Clamp Meter Auto Range Resistance Capacitance TesterNice little multi tester for AC/DC current up to 200A, voltage, resistance. I’m us…

off-grid-garage.com

For a nonprofessional setup, it requires some careful selection of procedures to measure capacity with common equipment (e.g a shunt and coulomb counter), but there are no guarantees of absolute accuracy other than 2% (+/-? 3 sigmas? 2 sigma, RMS who knows).
I'm only going to rely on capacity data (matched to the labels) right from EVE because I assume they can afford and use something at least as good as the off-grid garage.

People agonizing of voltage matching is pretty much irrelevant unless they can somehow ascertain that there was actually a change in voltage from a perfect match in transit. If you can't trust the vendors then you are already in an uphill battle trying to prove with hobby equipment that their "factory data" is in error.

I've been using the EBC-A40L since March, it is a great value if you need to test cells since it combines 40 amp charge and discharge along with data acquisition.
In total I have 7 different brands/makes of capacity testers, this is the one you should get if you want to verify the capacity of your cells. Tested against an instrument calibrated in January this year, it's very accurate (but all of them are, surprisingly).

 

[RV10flyer]

When I use three different load testers showing LiitoKala’s 280’s and Sanben’s 320 batches below what is advertised, then test Dongguan’s and Shenzhen Luyuan’s 280’s and all were over advertised. That’s all of the accuracy I need to tell me which vendors not to buy from.

 

[Posplayr]

I've been using the EBC-A40L since March, it is a great value if you need to test cells since it combines 40 amp charge and discharge along with data acquisition.
In total I have 7 different brands/makes of capacity testers, this is the one you should get if you want to verify the capacity of your cells. Tested against an instrument calibrated in January this year, it's very accurate (but all of them are, surprisingly).

If I was going to do any science experiments , then I would have bought the EBC-A40L .
But it doesn't do much good for cell arrays especially at 48V, so I'm relying on EVE not even the vendor.
If there's an issue somehow, then buying one would be the best way to deal with Alibaba if that was a concern.

People that are in this situation are doing themselves a disservice by measuring capacity at the array level (for evidence) as the manufactures will only recognize that at the cell level.

 

[houseofancients]

I've been using the EBC-A40L since March, it is a great value if you need to test cells since it combines 40 amp charge and discharge along with data acquisition.
In total I have 7 different brands/makes of capacity testers, this is the one you should get if you want to verify the capacity of your cells. Tested against an instrument calibrated in January this year, it's very accurate (but all of them are, surprisingly).

i agree, absolutely love mine

 

[houseofancients]

If I was going to do any science experiments , then I would have bought the EBC-A40L .
But it doesn't do much good for cell arrays especially at 48V, so I'm relying on EVE not even the vendor.
If there's an issue somehow, then buying one would be the best way to deal with Alibaba if that was a concern.

People that are in this situation are doing themselves a disservice by measuring capacity at the array level (for evidence) as the manufactures will only recognize that at the cell level.

you test cell by cell, or you can test a batch by putting them in parallel, however with these cell sizes , 16 280 AH cells at 40 A charge and discharge will take a while and will not allow you to root out single weak cells

 

[Posplayr]

you test cell by cell, or you can test a batch by putting them in parallel, however with these cell sizes , 16 280 AH cells at 40 A charge and discharge will take a while and will not allow you to root out single weak cells

Yes, clearly not something I want to do cell by cell.
I'm going to have 32 280 A-Hr for 16S2P where I'm more interested in how the array performs rather than the grade A matched cells.

 

[houseofancients]

I am about to embark on testing 202 280ah cells with the bc-a40l. It will take a loooong time. I will input the data into a spread sheet. I will of course be doing other things and this will be happening in the background. The purpose of the testing is to match cells into 16s packs of similar capacities. The thought is that I will create 12 16s packs that are not all limited by individual weak cells. The weak cells will live together in their own pack or packs and the strong cells will live together in their own packs. Hopefully I can gain the most overall capacity possible by doing this and as a side benefit, I will have the historical record of each cell so I can test any cell at a later date to determine cell degradation.

I have lots of stuff to do so testing the cells will be a process that will just proceed each time I walk into my office. It fer shur will be mighty teejis.

holy mozes 202..
are you going to do them all individually or in batches of 16 in parallel ?

 

[RV10flyer]

I am about to embark on testing 202 280ah cells with the bc-a40l. It will take a loooong time. I will input the data into a spread sheet. I will of course be doing other things and this will be happening in the background. The purpose of the testing is to match cells into 16s packs of similar capacities. The thought is that I will create 12 16s packs that are not all limited by individual weak cells. The weak cells will live together in their own pack or packs and the strong cells will live together in their own packs. Hopefully I can gain the most overall capacity possible by doing this and as a side benefit, I will have the historical record of each cell so I can test any cell at a later date to determine cell degradation.

I have lots of stuff to do so testing the cells will be a process that will just proceed each time I walk into my office. It fer shur will be mighty teejis.

The same way I did with all of mine. 160.

 

[Just John]

If you are doing a large number of cells, best to use a BMS and charge until high voltage disconnect on a cell. Then it will be much faster charging each cell on the tester, discharging for the capacity test, and then you can either charge each cell to a storage voltage on the tester or use another power supply to get them to storage voltage.

 

[Just John]

I have multiple power supplies. I will charge to almost full on a separate power supply and then switch over to the EBC A40L to top off and do a discharge test. I will then start charging the next cell in line while the discharge test is happening and will also recharge the recently tested cell with a third power supply. I will use another power supply to top balance each 16 cell grouping once the grouping is determined. It's a process with a few moving parts. The trick is to always stop and confirm before attaching a lead to a cell. Never attach to a cell without stopping and thinking carefully about polarity. Other than that it's just tedious and time consuming. I kind of wish I had committed to a second capacity tester but I would have wanted another pc. I don't use pc so I had to dig out an old dead laptop from years ago and get it up and running enough to load the application for the EBC A40L on it and now it will just stay on for a couple of months and then go back into the attic.(conditioned attic)

I use Anderson connectors to prevent mix-ups. Yes, you can still connect things wrong, but once you have the cable attached, no thought is required. I have a busbar with two 40 amp power supplies attached, and 4 Anderson connectors attached, so I can parallel 4 cells (great for top balancing).

I can also parallel some 40 amp loads using the busbar setup. But this is using separate testers, not the EBC-A40L.
I certainly have given thought to replacing the alligator clips on the EBC-A40L, but haven't done so yet. I'm using 8 gauge Ancor wire, and some Ancor lugs (they have the best plating) with 50 amp rated Anderson connectors.

Yes, I'm doing lots of testing, trying to quantify how the cells age. The EBC-A40L makes it really easy to save the data files so you can compare as the cells age.