EVE 280A Load Capacity Testing Help Wanted

[Stepandwolf]

From reading others reviews of what they received using the group buy, I would say you are MUCH more likely to have received grade A cells.
Most vendors on Aliexpress and Alibaba are buying factory rejects and slapping labels on them saying grade A, when they are not (and even worse, the seller KNOWS they are not grade A).

With the group buy, the vendors/sellers have a vested interest in delivering high quality cells, because Michael will send more orders their way, and drop anyone who is delivering obviously fraudulent cells. Incentives work.

However, Michael's customers, or at least some of them got boxes of crap. I don't just mean improper packing and handling, but obvously used, damaged cells. So even Michael and his customers can get screwed. As a rule, his group buying power ought to insure the highest quality product for the reasons you mention, but it didn't happen that way for a lot of people. My "on my own" purchase worked out quite well.

 

[Stepandwolf]

It depends on which version of the spec sheet you read. The version I purchased has it, but I see the later versions have dropped it.

5.1 Standard Test Conditions
Test should be conducted with new batteries within one month after shipment from our factory and the cells shall not be cycled more than five times before the test. Unless otherwise defined, test stated in this specification should be conducted at temperature of 25±2℃, humidity 45~85% and Test should be performed under standard atmospheric conditions with 86KPa~106KPa pressure.

EVE LF280 (3.2V 280Ah) Product Specification (Version E)-2019.7.5

Most recent Spec Sheet for the 280 LFP cells as provided directly by EVE March-14-2020.

diysolarforum.com

This is not for matched, this is for grade A. Matched cells should remain matched for their entire life, it is different than grade A. Certainly "matched" implies grade A when new, but cells can still be matched after use as long as the set is used as a set evenly.

Basically it seems like that month rule would be for their Chinese vendors as no customer will ever see a battery that is a month old. I assume typically the average end user doesn't see data or product sheets and would be oblivious, like a customer buy a Battle Born. They have no idea what is inside, age, or anything.

 

[Just John]

However, Michael's customers, or at least some of them got boxes of crap. I don't just mean improper packing and handling, but obvously used, damaged cells. So even Michael and his customers can get screwed. As a rule, his group buying power ought to insure the highest quality product for the reasons you mention, but it didn't happen that way for a lot of people. My "on my own" purchase worked out quite well.

I'd bet money that Michael stopped using those suppliers. As a whole, you are much more LIKELY to get a quality product from the group buy, but I don't doubt that fly by night vendors creep in with low prices to tempt him, and get dropped when he finds out they deliver garbage.

Me, I like a sure thing, and I'm willing to pay for it, but I'm definitely in a minority in that regard.

 

[Just John]

Basically it seems like that month rule would be for their Chinese vendors as no customer will ever see a battery that is a month old. I assume typically the average end user doesn't see data or product sheets and would be oblivious, like a customer buy a Battle Born. They have no idea what is inside, age, or anything.

You can actually get air shipping, but man do you pay for it. More shipping than battery costs then.

Yes, the primary market for these cells is the vehicle manufacturers in China (subsidized by the Chinese government).
The Chinese government doesn't subsidize directly, but they control how many vehicle licenses are issued. Currently the wait for a license allowing you to buy an ICE vehicle is over a year, not so for an EV. So, if you want a car in China, better buy an EV no matter the price difference.

Anyway, we are even less than an afterthought for the manufacturers, we are basically an annoyance.

 

[Stepandwolf]

You can actually get air shipping, but man do you pay for it. More shipping than battery costs then.

Yes, the primary market for these cells is the vehicle manufacturers in China (subsidized by the Chinese government).
The Chinese government doesn't subsidize directly, but they control how many vehicle licenses are issued. Currently the wait for a license allowing you to buy an ICE vehicle is over a year, not so for an EV. So, if you want a car in China, better buy an EV no matter the price difference.

Anyway, we are even less than an afterthought for the manufacturers, we are basically an annoyance.

Some vendors quoted me air....I wasn't in that much rush and when you can buy from CA, I think air from China is unnecessary.

 

[Just John]

Some vendors quoted me air....I wasn't in that much rush and when you can buy from CA, I think air from China is unnecessary.

I think you are more likely to get grade A cells from California, simply because it costs money to set that up. Thus you are less likely to get vendors selling e-waste, because charge backs and people sending back inferior products are much more likely. But they are not cheap, and you can still get grade B cells, just not as likely. A lot of the shady vendors are counting on the average buyer not being able to test, or taking too long to test. If you live in the Phoenix area and have cells coming in, drop me a line, I have the right equipment to get it done quickly.

 

[Stepandwolf]

I think you are more likely to get grade A cells from California, simply because it costs money to set that up. Thus you are less likely to get vendors selling e-waste, because charge backs and people sending back inferior products are much more likely. But they are not cheap, and you can still get grade B cells, just not as likely. A lot of the shady vendors are counting on the average buyer not being able to test, or taking too long to test. If you live in the Phoenix area and have cells coming in, drop me a line, I have the right equipment to get it done quickly.

I should have packed up my cells and brought them over....I bought my SUV in PHX.

 

[Just John]

I should have packed up my cells and brought them over....I bought my SUV in PHX.

Yes, I can easily test 5 at a time for discharge and charge at 40 amps.
I have the cell tester, plus a 40 amp power supply (with a BMS to charge 4 at a time), and then 4 of the electronic loads that are capable of 40 amps.

I do have more loads, but most are cheaper ones like you have. I have 4 of the electronic loads, because hooked up to a busbar you can test a single cell at .5C, or a full battery pack (12v) at over 100 amps. I have Anderson connectors on the busbar so I can parallel all 4 electronic loads very easily.

 

[Stepandwolf]

I was looking at land by Prescott not long ago.

 

[Just John]

I was looking at land by Prescott not long ago.

Yes, I have considered that as well. My only concern would be forest fires. With starlink and solar power, now you can pretty much live anywhere and really only have to worry about adequate water supply and natural disasters. I was also looking at Flagstaff and the Showlow area.

 

[Stepandwolf]

Yes, I have considered that as well. My only concern would be forest fires. With starlink and solar power, now you can pretty much live anywhere and really only have to worry about adequate water supply and natural disasters. I was also looking at Flagstaff and the Showlow area.

I have lived in jungles, deserts, deciduous, but never pine. I hope if a fire is coming I will have a warning. The property I was looking at is basically the peak of a mountain, or a ridge off of the peak... 4 mining claims on the property from way back..

I know via YT nomads, boondockers, etc....winter in Quartzite, summer in Flagstaff. Some of them also travel around in the summer, but are coming back to roost soon. Point is, they are traveling on 10 and 40 so Prescott, etc. puts you between, it also puts you between in temp. I know someone who just bought and sold in Cloudcroft as his "northern" basecamp.

A customer is moving to Sierra Vista when he retires...

I would be OK moving from here to AZ, possibly, but don't want a north and a south...just one nice one.

edit: right now, 99 Phoenix, 78 Prescott, 57 Flagstaff and 86 here at home.

 

[Stepandwolf]

Hi guys....just finished the 8th EVE cell and am happy to report that all the cells tested out great and all tested between 286 and 288V so they are all over spec and all similar to each other. Now that the EVE's are all tested, and I have a tester now, I can go back and test the Lishens as they never were load tested. Received in January, top balanced, and just sat on my workbench since. My second, replacement tester, was supposed to arrive Friday but was delayed until Monday. Hopefully I can get the eight Lishens tested before returning the first load tester.

Thanks to everyone for all their help, suggestions, and tips!

 

[Just John]

Hi guys....just finished the 8th EVE cell and am happy to report that all the cells tested out great and all tested between 286 and 288V so they are all over spec and all similar to each other. Now that the EVE's are all tested, and I have a tester now, I can go back and test the Lishens as they never were load tested. Received in January, top balanced, and just sat on my workbench since. My second, replacement tester, was supposed to arrive Friday but was delayed until Monday. Hopefully I can get the eight Lishens tested before returning the first load tester.

Thanks to everyone for all their help, suggestions, and tips!

I would be interested in how your Lishen test out. Most reports were very good.

 

[Stepandwolf]

I would be interested in how your Lishen test out. Most reports were very good.

I noticed they swelled a bit...weren't under compression.

 

[Berseker]

Hi guys....just finished the 8th EVE cell and am happy to report that all the cells tested out great and all tested between 286 and 288V so they are all over spec and all similar to each other. Now that the EVE's are all tested, and I have a tester now, I can go back and test the Lishens as they never were load tested. Received in January, top balanced, and just sat on my workbench since. My second, replacement tester, was supposed to arrive Friday but was delayed until Monday. Hopefully I can get the eight Lishens tested before returning the first load tester.

Thanks to everyone for all their help, suggestions, and tips!

.
did you test at 1c or 0.5c?
COULD YOU SHARE WHAT load tester you used. am hunting for an affordable 1C load tester for my rept cells, no hits. max i saw was 40amps load tester

 

[Just John]

.
did you test at 1c or 0.5c?
COULD YOU SHARE WHAT load tester you used. am hunting for an affordable 1C load tester for my rept cells, no hits. max i saw was 40amps load tester

If you want to test at higher rates, use a shunt and your inverter for a pack. For individual cells, just hooked up multiple loads and add their measured capacity when done.

 

[chrisski]

If you want to test at higher rates, use a shunt and your inverter for a pack. For individual cells, just hooked up multiple loads and add their measured capacity when done.

I like this idea of using a shunt, but the one I found capable of this is the Victron Smart Shunt, which is about $100 alone or $200 with the meter. I purchased an Ailii shunt recommended to me by a user and I see Will uses these and it is between $20 and $40, but has no data logging capabilities. I can see how many amps I use now on the AiLi, but not how many amp hours expended.

Also neither has a cutoff voltage like a true capacity tester, unless you’re running to the low voltage cutoff of the inverter. If the low voltage cutoff of the inverter is 10 volts, than you match the 12 volt low voltage cutoff of 10 volts. My 12 volt inverter cuts off at 10.5 volts, so a capacity test done this way will not show a full capacity. So, I have no idea what 2.625 is per cell SOC wise, or even if all 4 cells would be balanced at that point, but I do know I can’t take these cells below 2.5 VDC. This also does not provide individual cell data, only groups of 4.

Honestly though, I am not looking forward to spending three weeks charging my 16 eve cells on a 10 amp power supply, and then discharging them at 20 amps, and then recharging them. THat would get me good individual data to group my 16 cells into balanced groups of 8.

I did get the spec sheet for each battery for from China before they shipped. I’m thinking of double checking the by purchasing a $75 battery internal resistance tester and if that checks out, not spend the next three weeks capacity testing. If the internal resistance checks out, then I would just build the packs based off the spec sheet. I would top balance before doing the resistance check.

I capacity tested 11 cells to make an 8 cell 25 ah battery, and I have to say I did not enjoy that at all.

That is three weeks done efficiently with 16 cells, 280 ah each, a 20 amp battery tester that auto cuts off at 2.5, and a power supply that can charge each cell at 10 amps, and since I need to do things like work and sleep, that would easily turn into six weeks.

 

[Stepandwolf]

.
did you test at 1c or 0.5c?
COULD YOU SHARE WHAT load tester you used. am hunting for an affordable 1C load tester for my rept cells, no hits. max i saw was 40amps load tester

I only have a .0001C tester It is the 150W load tester that only draws 12A with my setup. Does that make it a .08 load tester if my math is right?

 

[Stepandwolf]

If you want to test at higher rates, use a shunt and your inverter for a pack. For individual cells, just hooked up multiple loads and add their measured capacity when done.

Way too complicated for my senile mind. My inverter is still untouched...on the bench, never seen a wire. Same with my shunt, all just sitting there waiting for the build I keep procrastinating on.

For those who are following my antics, I began testing the Lishen 272A cells from Michael I received in January, top balanced, and parked until now. Didn't have the load tester then so I didn't do anything else with them. Now I am testing them and have done two so far. First was 280.9, the second one was 281.4. Was the rumour that these were actually 280A cells that were sold as 272 so everyone would be happy?

 

[Stepandwolf]

I like this idea of using a shunt, but the one I found capable of this is the Victron Smart Shunt, which is about $100 alone or $200 with the meter. I purchased an Ailii shunt recommended to me by a user and I see Will uses these and it is between $20 and $40, but has no data logging capabilities. I can see how many amps I use now on the AiLi, but not how many amp hours expended.

I have the Victron shunt with BM712 meter, collecting dust.

Honestly though, I am not looking forward to spending three weeks charging my 16 eve cells on a 10 amp power supply, and then discharging them at 20 amps, and then recharging them. THat would get me good individual data to group my 16 cells into balanced groups of 8.

The top balancing took awhile which is how I got them all to 3.65. With it taking a day to load test one cell, it can be arduous.

That is three weeks done efficiently with 16 cells, 280 ah each, a 20 amp battery tester that auto cuts off at 2.5, and a power supply that can charge each cell at 10 amps, and since I need to do things like work and sleep, that would easily turn into six weeks.

Have a secret for you....you can actually go to work, eat and sleep while charging and testing is going on. We don't all have to live in our garage like Andy