16 EVE LF280K (3.2V 280Ah) Cells

[guidecca]

I purchased 16 cells locally in August 2021. It is May 2022 and I'm putting a 8s2p 24v system together. All cells tested 3.29v except for the last cell which tested 0.8 v. I am charging it now to 3.29v; is the bad cell ruined or do I continue charging it? I believe the bad cell tested 3.29v when I bought it. Does Basen offer a five year warranty? I need one cell to complete the battery. Where is the best and quickest source for me to replace one cell? This is some bad luck.

 

[740GLE]

What current are you putting into the low voltage cell? Hopefully nice a low.

If it holds the voltage after resting it might be good.

 

[guidecca]

Its charging at 1.5A. Was thinking this situation is a good reason to buy 17 cells vice 16 cells. I let it charge all night at 3.29v and the voltage measured 3.24v in the morning, so I increased the charger voltage to 3.40v; the battery is still reading 3.24v on the multimeter. But, the charger indicates the cell is at 3.3v so there is a discrepancy between what the charger says and what my multimeter says. Why is there a discrepancy between the charger and the multimeter? And why is the cell charging so slowly?

 

[740GLE]

The cell is most likely damaged/compromised. If you disconnect the charger let it rest for 12hr then note how much the voltage dropped. My guess is quite a bit.

 

[joanna_lannie]

The quickest source for a replacement battery should be a battery supplier with a local warehouse. If you're in the US, it's easy because most battery suppliers have local warehouses in the US and you can receive the battery in a very short time. But it's important to note that you should check with your consulted battery supplier, for one thing, you need a battery that can match your system voltage. In addition, too cheap LiFePO4 battery is basically a scam, beware!

 

[DerpsyDoodler]

The cell is most likely damaged/compromised. If you disconnect the charger let it rest for 12hr then note how much the voltage dropped. My guess is quite a bit.

Its most likely compromised because of the low voltage, not because the discrepancy between charger and multi-meter. there could be any number of reasons for that, namely that the charger pushes a higher voltage to charge the cells. if guid takes the voltage at the charger terminal with his multi-meter, he'll likely read something close to the charger voltage.Crappy leads will cause a lot of voltage drop too. That said, these cells take a long time to charge anyway. at 10Amps it will take at least 28 hours (actually more) to reach 100%. This isnt accounting for the 1.5 amps for however long. Bottom line is its not a quick process. At least he started charging slow.

@guidecca Is the cell bulging or malformed? I know you're supposed to charge an over-discharged cell very very slow to start with, but i dont know how slow or what the process is off-hand. There are threads on this forum about it.

 

[guidecca]

Its most likely compromised because of the low voltage, not because the discrepancy between charger and multi-meter. there could be any number of reasons for that, namely that the charger pushes a higher voltage to charge the cells. if guid takes the voltage at the charger terminal with his multi-meter, he'll likely read something close to the charger voltage.Crappy leads will cause a lot of voltage drop too. That said, these cells take a long time to charge anyway. at 10Amps it will take at least 28 hours (actually more) to reach 100%. This isnt accounting for the 1.5 amps for however long. Bottom line is its not a quick process. At least he started charging slow.

@guidecca Is the cell bulging or malformed? I know you're supposed to charge an over-discharged cell very very slow to start with, but i dont know how slow or what the process is off-hand. There are threads on this forum about it.

The cell is not bulging or malformed. It is still charging at 1.5A and the charger says it is almost up to 3.29v. What the actual voltage of the cell is I don't know. I'm using the stock leads with the alligator clips; was planning on changing the leads out with 8 or 10 gauge wire leads when the time came. This battery was still in the original shipping box. A new unused Grade A cell should not lose voltage is the bottom line.

 

[guidecca]

What do you do with one cell that drops voltage very very slowly, by single hundredths of volts over time? Incorporate it into the system and keep an eye on it? I've emailed Basen China about the problem and tried to chat with Basen USA via their website; they don't answer. If the other cells are spot on 3.29v will this one cell screw things up?

 

[740GLE]

If you feel the cell can still be viable in your set up, keep an eye on it and the BMS will flag it as a runner. You doing a 48v system? If it is compromised, it’ll cut the entire pack capacity down quite substantially due to low cell cut off and high voltage disconnect.

 

[guidecca]

I'm doing 8s2p 24v system with two eight cell group in series and parallel using two BMS's. I charged it to 3.29v this morning and as we speak it is down to 3.280; I don't have a warm and fuzzy about it but the only battery person who has answered up is the guy I bought them from. Basen USA and Basen China maintaining radio silence, lol; that battery is in stock on their website. Don't feel like I should have to pay twice for one cell but we're in the process of changing solar panels from 400W to 1265W with all those issues.

 

[AKvalleyguy]

Basen USA and Basen China maintaining radio silence,

Thanks for including a brand, helps with the "good vendor-bad vendor" list.

 

[guidecca]

Thanks for including a brand, helps with the "good vendor-bad vendor" list.

This cell is barely 12 months old and has a 5-year warranty according to Basen but they refuse to replace it. She babbles on about an "ov" over voltage? Not by me.

Manufacturer: EVE sold by Basen
Power Product Type: Battery Cell
Battery Type: LiFePO4
Norminal Capacity: 280Ah (LF280K)
Norminal Voltage: 3.2V
Production Date: 09/Apr/2021

The sales manager, Gloria Luo, at Basen said this:

Thanks for the detailed information, as we understand at present, as the battery already storage over 1 year, and got one cell to 0V with not charge during storage time( normally will charge and discharge one cycle during every 3 months storage to keep it active ), after recharged and activated it, which might caused the difference between the cells.

We recommend to test the battery internal resistance:
if shows normal with other cells, No.16 is ok for using, and then charge all cells to 3.65V , finish a top balance to get same condition on all cell.
If shows much different with other cells, we do recommend to purchase a new one replacement.

Any doubts or needs, do feel free to contact us.

Best Regards,
Gloria L

 

[time2roll]

I'm doing 8s2p 24v system with two eight cell group in series and parallel using two BMS's. I charged it to 3.29v this morning and as we speak it is down to 3.280; I don't have a warm and fuzzy about it but the only battery person who has answered up is the guy I bought them from. Basen USA and Basen China maintaining radio silence, lol; that battery is in stock on their website. Don't feel like I should have to pay twice for one cell but we're in the process of changing solar panels from 400W to 1265W with all those issues.

I don't think it will be known until all are top balanced and then check where all 16 settle from 3.650 volts. The 3.280 just does not tell much on how this cell will hold up. After top balance in parallel consider assembling 8s (no parallel) including the suspect cell and see if the suspect cell drops way low before the others.

Depending on the result get a replacement cell or connect all in 8s2p and connect for service. Time to move forward.

 

[AKvalleyguy]

Lot of good ideas tossed out. As others have said, I will just list;

1) As DerpsyDoodler suggests, It takes a long time to charge these cells at a low amperage. If you are using a benchtop power supply, the alligator leads are ridiculously inefficient. You will get some juice going by making some heavy gauge leads. Also, if you do the ring terminal and 10awg wire thing, I found it helps, in my case, to also use the alligator leads. They both work fine together. I suppose that's okay?

2) As 740GLE suggests, let it rest and see where it settles in. I would leave it on the charger as long as you can stand it, as long as it isn't getting all weird bulgy and heating up. See what voltage it will climb to, then let it settle in.

3) As Time2roll suggests, go forward with the top balance. Then build the battery with the suspect cell and see how it goes. When you get the BMS hooked up, you will figure out pretty fast if the suspect is going to roll over and play dead.

4) As Joanna_lannie says, If you are in the lower 48 States, getting extras will be quick and painless. Seems like Basen has tossed you to the curb.

5) IDK, maybe it's being to hopeful for that poor cell. Maybe we're just supplying you with a hit of hopium thinking that it will be okay. Personally never dealt with one of these LiFePO4's that hit a bottom voltage like that.

 

[guidecca]

Lot of good ideas tossed out. As others have said, I will just list;

1) As DerpsyDoodler suggests, It takes a long time to charge these cells at a low amperage. If you are using a benchtop power supply, the alligator leads are ridiculously inefficient. You will get some juice going by making some heavy gauge leads. Also, if you do the ring terminal and 10awg wire thing, I found it helps, in my case, to also use the alligator leads. They both work fine together. I suppose that's okay?

2) As 740GLE suggests, let it rest and see where it settles in. I would leave it on the charger as long as you can stand it, as long as it isn't getting all weird bulgy and heating up. See what voltage it will climb to, then let it settle in.

3) As Time2roll suggests, go forward with the top balance. Then build the battery with the suspect cell and see how it goes. When you get the BMS hooked up, you will figure out pretty fast if the suspect is going to roll over and play dead.

4) As Joanna_lannie says, If you are in the lower 48 States, getting extras will be quick and painless. Seems like Basen has tossed you to the curb.

5) IDK, maybe it's being to hopeful for that poor cell. Maybe we're just supplying you with a hit of hopium thinking that it will be okay. Personally never dealt with one of these LiFePO4's that hit a bottom voltage like that.

I don't understand LiFePO4 chargers. Would this charger work to pre-balance EVE LiFePO4 3.2v 280Ah batteries?
https://www.amazon.com/ExpertPower-...NDRH/ref=cm_cr_arp_d_product_top?ie=UTF8&th=1

 

[time2roll]

I don't understand LiFePO4 chargers. Would this charger work to pre-balance EVE LiFePO4 3.2v 280Ah batteries?
https://www.amazon.com/ExpertPower-...NDRH/ref=cm_cr_arp_d_product_top?ie=UTF8&th=1

This charger will need to charge the cells in series as it is 12v nominal.

I assume a "pre-balance" is cells in parallel charging to 3.650 volts. Need an adjustable power supply of 10+ amps for this process.