EVE 280Ah Lifepo4

[Maast]

I just received my 4x Lifepo4 280Ah Batteries for the camper. After looking around I opted to try my luck with Dongguan Billion Electronic Technology.
The cost per cell was 72$ (288$ total) and 220$ for shippint to Canada via UPS. Duty and brokerage was 55$ CAN

I recognize those cells, I've got one that in the que for my torture and lifecycle testing. Thats one heck of a deal on the cells, I paid $125 for just one and then shipping on top of that.
Of the 5 cells I've received it holds its storage voltage the best. If I remember right initial capacity testing gave me 283AH.

 

[msdmaddog]

so the cells just perform well Maast ? how many cycles ? how many months / years ? any problems ?

 

[April]

A slightly different method, better or worse ? At least you can bottom out the "bolt" and back it off 2 turns before hand tightening the nut & final tightening, more tedious & fiddly (gotta be extra tool cautions). I'm surprised this is not the standard method but I'm sure there are varied reasons.

Mechanically you should have a washer between bar and nut so the nut does not rip into bar.
I like that system however but the cost is a factor too.

 

[April]

The fourth picture looks broken. It's very dangerous.

Nah the aluminium is quite thick and would need to be pierced . Theres no pressure inside and LiFePo4 is not dangerous.Worst that will happen is electrolyte/coolant leaks out and stains stuff.

 

[Steve_S]

Mechanically you should have a washer between bar and nut so the nut does not rip into bar.
I like that system however but the cost is a factor too.

That is not my own build. That is the ShunBin pack and their doing with the aluminium bar stock, which I am replacing with proper copper. the 24v/400AH pack cost 2999 usd / 3999 cad, crappy bms and questionable cells. Would have cost the same to build a pack with the upgraded BMS etc. Lessons Learned expensively.

 

[Maast]

so the cells just perform well Maast ? how many cycles ? how many months / years ? any problems ?

I dunno yet, it's in the line to be tortured next. I've got a GFB277 on the tester now and at .5C I only get 6 cycles per day so it takes a looooOOOOOOOoong time (weeks and weeks) to do enough cycles to get enough data to extrapolate lifecycle. So far all I've done to the cell model the OP bought is initial capacity testing and charge voltage holding, which it passed.

For what was paid for them though I do have to wonder if its a B or a C cell. Or did I just get ripped off. The quickest test of a quality of a cell after capacity is how well it holds a charge after its been charged up to 3.65v per cell. It should drop quickly (hours) to roughly 3.5 but then hold that for at least a week before dropping below 3.5 or 3.45 at worst. Capacity and charge holding capability is the first test from the factory to differentiate an A from a B from a C cell.

I hope the OP tests the snot out of his and posts the results, I'm super curious and at that price point if they're decent cells I'll be upping the number of cells I'll be buying myself from them. I got mine from a completely different vendor.

 

[Maast]

Nah the aluminium is quite thick and would need to be pierced . Theres no pressure inside and LiFePo4 is not dangerous.Worst that will happen is electrolyte/coolant leaks out and stains stuff.

For what it's worth, I got 4 cells without holes or terminals on them, on the first I gingerly drilled down 1mm at a time on my drill press and discovered the aluminum post is quite thick and very soft. The first hint of copper color was at 3/4 an inch. I then tapped it and then installed a 1.75" bolt, wrapped a strip of wet paper towel around the base of the bolt then cut the head of the bolt off with a grinder then tapered it.

The next three I bypassed the tapping and just drilled the hole, screwed in the bolt, unscrewed it and sanded off the ridge that formed around the hole, screwed it back in and cut the bolt head off. Saved a lot of time.

You can easily feel when it bottoms out and all you need then is just a couple of inch-pounds to secure it.

 

[msdmaddog]

iam very excited about your results and thx you for that very helpful information Maast

 

[April]

For what it's worth, I got 4 cells without holes or terminals on them Never seen that on any advertised cells?
The first hint of copper color was at 3/4 an inch. Its the tabs squeezed together then a 1/8th rectangle of copper is spot welded to the bottom of the terminal with the tabs between . If you see copper you see the tabs
You can easily feel when it bottoms out and all you need then is just a couple of inch-pounds to secure it. If you do that you risk separating the spot weld allowing air into the cell and leaks out

 

[Johan]

Nah the aluminium is quite thick and would need to be pierced . Theres no pressure inside and LiFePo4 is not dangerous.Worst that will happen is electrolyte/coolant leaks out and stains stuff.

@TJ Tom, @April, @boboxx

Related to the visible aluminium damage (I have no idea whether the damage could be a problem), just as a reference I wanted to share:

NordkynDesign - lithium battery banks fundamentals,

in turn referring to (search for "edge", e.g. p32):

Lithium-Ion Batteries Hazard and Use Assessment, Exponent Failure Analysis Associates, Inc., published by the Fire Protection Research Foundation (2011)

 

[boboxx]

I have been playing with my batteries for a bit now but I have a problem. I have on cell that has a dark blue wrap, it's different from the 3 other ones.

If I put my Virctron 10amp charger on the pack, 3 batteries will reach about 3.35v and the dark bleu will be way off. The fist time I had it charging it reached 4.02v before I noticed it! I installed one of these BMS (https://www.ebay.com/itm/322387253365) and it can keep the battery ballaced but cell will never pass 3.5v.

If I use one of the small active balancer at 1.2amp (https://www.ebay.ca/itm/312774496524) it dosen't look like it can keep up as the cells are out of balanced again (3.35, 3.35, 3.35, 3.86). I have a 5A Active Balancer on order to try out. (https://www.ebay.ca/itm/312799154132)

If all cell are equal at 3.35v and I use the inverter to drain they all go down at the same rate.

I figured I would ask in case someone knows what the issue might be and how I could resolve

 

[Maast]

I sounds like you got a cell with a much lower capacity than the others and there's no fixing that - at best you can mitigate it with a high amperage active balancer but thats a poor fix. I'd measure capacity of the 'good' cells and buy a replacement cell of the same capacity. The highest amperage active balancer that I know of is this one at 6A, but they're not cheap and you need one per cell.

Led Indicator 1S Battery Equalizer Balancer BMS Active 18650 Polymer DIY for sale | eBay

Find great deals on eBay for Led Indicator 1S Battery Equalizer Balancer BMS Active 18650 Polymer DIY. Shop with confidence.

www.ebay.ca

You can find these cheaper on Aliexpress but the best price is still $20 US a unit, they also make 8S ones that are already ganged together for a bit less per-cell cost.

 

[boboxx]

Ya it's a bummer, how do I know that the 3 other cell are good?

If I would want to charge the cell individually, with a bench top power supply, would it be ok to just set the voltage to 3.65v@3a?

 

[Maast]

Ya it's a bummer, how do I know that the 3 other cell are good?
If I would want to charge the cell individually, with a bench top power supply, would it be ok to just set the voltage to 3.65v@3a?

Exactly, then a hall effect amphour meter and dump it to a load of some kind. FYI a 15 inch length of .032 stainless wire will draw about 5 amps at 3.3V, parallel a few of those and drop it in a bucket of water and you've got yourself a cheap and easy loadbank.

 

[boboxx]

Thanks Maast, have you noticed similar with the battery you got or are they all good cell?

 

[Maast]

So far they've been good, different capacities with different battery models but thats to be expected.

 

[Johan]

I added some terminal bolt torque info here.

 

[boboxx]

Those are nice!

 

[backwash]

Good day everyone; I also just popped for 8 of these EVE 280ah cells for our 5th wheel. (planning on a 4s2p for 12v bank) they should be here in a few weeks and I'll keep everyone apprised of the progress and results. I know they'll be grade B cells. but at this price and the expected low consumption I don't anticipate too many problems with using them and putting together a nice 12v bank. Will most likely also go with a pair of 5A active balancers which I also just ordered to try out. Will be glad to be rid of my FLA bank. (which weighs in at about 250# in the cargo bay)

 

[Barold]

Good day everyone; I also just popped for 8 of these EVE 280ah cells for our 5th wheel. (planning on a 4s2p for 12v bank) they should be here in a few weeks and I'll keep everyone apprised of the progress and results. I know they'll be grade B cells. but at this price and the expected low consumption I don't anticipate too many problems with using them and putting together a nice 12v bank. Will most likely also go with a pair of 5A active balancers which I also just ordered to try out. Will be glad to be rid of my FLA bank. (which weighs in at about 250# in the cargo bay)

Did you also order from Billion Electronic Technology on Alibaba? I am getting a quote for shipping - though I don't know what to make - they claim these are Grade A cells...