42OhmsPA
Who likes Electrical Gremlins?
Thank you for checking.
Wow, I really like the layout of that software... It makes the JBD look like jumbled battery data.
Adding a 1/2 dozen new BMS to the shopping list.
A ton of LiFePo⁴ cells
- Thread starter Spunky
- Start date
Wow, I really like the layout of that software... It makes the JBD look like jumbled battery data.
Adding a 1/2 dozen new BMS to the shopping list.
Spunky
Solar Enthusiast
Seplos seems to have good reviews, just wasn't sure how they'd get along with what I have. I monitor my 14 SOKs with SolarAssistant, which are fairly predictable now. I was hoping I could swap RS-232 cables when I wanted to see the new bank without changing anything else.
GobelPower has Pace for sale too.
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SalmanFarooz
New Member
This is a wonderful thread I think I will do something very similar! I currently have 2 SOK 100AH 48v and I am looking to expand, I think you can save a lot of money buy building the battery, the software shown is exactly what my SOK uses so getting the cells & BMS will be fantastic. I heave a heavy duty dewalt shelf I think I can make a 3 story battery shelf and use some threaded rod to keep the cells clamped together.
Spunky
Solar Enthusiast
Thanks. My day job kept me busy for 18 days straight, so not much happening at home.
I ordered 4 more cells, this time from 18650 (small order price advantage), because out of 240 cells, I received 160 and the highest and lowest of the bunch (was missing cells from the middle).
I'm not sure, if that amount of difference between 157 & 160 would be a problem down the road, but I don't want to move these heavy batteries again. I could make sure that one ended up on top and maybe install a HelTec in it with a switch too.18650 didn't include an EVE test sheet and have been unresponsive to my emails, but their shipping was quick and quality. I'll call them today.
Attachments
That's capacity tolerance of only 1.43%. The graph looks way worse due to vertical scale starting at 298Ah instead of 0.
wfdTamar
New Member
Ignore
Spunky
Solar Enthusiast
All of the LF280K V3 cells are over 300Ah. But I wouldn't mix the 304 with the 300 in the same battery (matched batch or not).
If that last group of 16 is good enough for a BMS that has balancing, those other 9 will surely be primo.
Either way, I ordered 4 more cells that should push that low 300Ah off the list and into a future 12v 4S project.
How much difference is allowable in a 300Ah battery?
I have 14 - 100Ah, 51.2V batteries running together and one of them kept misbehaving. I would open it up, manually balance it and put it back to work. A few months later, the same deal, same low cell. So upon testing the low cell compared to the higher ones, turned out that the low cell had the highest Ah capacity. Only a little over 1Ah, but changing it out seems to have solved the issue.
Still waiting on 18650 to send the test info I requested, I called and talked to someone that was going to forward my email to management. Looking like I'll have to test them myself (there's only four) in my spare time ?
Alkaline
Solar Wizard
Please see what scores they have, SFK is claiming there are 2 version of the version 3, one with octagon base and one with round base that have the eve dual hole terminals. The octagon base are testing higher according to them, If you can get the sheet from 18650 can you post some screenshots of it to see if the range is around 300 or is it around 312.
Thanks
Max charge voltage 54.4V without balancer after built, may be not that good for grade A cells?
We have built many packs using Grade A EVE 280Ah, most pack can be charge to 57V above without balancing, only several were charged to 56.5V-57V while one cell reaches to 3.65V. May be charging method is not same?
www.gobelpower.com
Test report here has no OCV3 Time column. This is different from report we get.
OCV3 Time really matters even though time value itself is not useful.
We have built many packs using Grade A EVE 280Ah, most pack can be charge to 57V above without balancing, only several were charged to 56.5V-57V while one cell reaches to 3.65V. May be charging method is not same?
Battery Pack Information Lookup : GobelPower.com
GobelPower.com : Battery Pack Information Lookup - China Lithium Battery Distributor and manufacturer, Offers LiFePO4 Battery, 18650 Battery, 12V/24V/48V/72V Rechargable Lithium Battery for Home Solar Energy Storage, Electric Bikes, Scooters, Forklifts, Sweepers, Mowers and Boats.
Test report here has no OCV3 Time column. This is different from report we get.
OCV3 Time really matters even though time value itself is not useful.
Spunky
Solar Enthusiast
Some quick pix before going to work. I'm seeing some hex in there. And I'm sure 18650 is selling legitimate goods: 04QCB76G40703JD9F0008513
High res pix are in thumbnails below. 1st is SFK and 2nd is 18650 (hexagonal).
Testing will start as soon as I get home.
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Brucey
Velcro Man
So the round terminal V3 tests around 300 and the octagonal V3 tests at 312. What does the V2 test at?
Is the octagonal actually basically a V4? Makes me want to just get the 304s to avoid all this nonsense with the 280K series.
Alkaline
Solar Wizard
Both SFK and 18650 dual pole are round base I think if you buy the EVE terminals they only come with the round base.
to get the octagon base you have to get it without the EVE terminals
batteryhookup is the same way, the octagon base is about 10-12 ah higher but it comes with the typical little button stud.
Alkaline
Solar Wizard
Max charge voltage 54.4V without balancer after built, may be not that good for grade A cells?
We have built many packs using Grade A EVE 280Ah, most pack can be charge to 57V above without balancing, only several were charged to 56.5V-57V while one cell reaches to 3.65V. May be charging method is not same?
View attachment 184300
Battery Pack Information Lookup : GobelPower.com
GobelPower.com : Battery Pack Information Lookup - China Lithium Battery Distributor and manufacturer, Offers LiFePO4 Battery, 18650 Battery, 12V/24V/48V/72V Rechargable Lithium Battery for Home Solar Energy Storage, Electric Bikes, Scooters, Forklifts, Sweepers, Mowers and Boats.
View attachment 184301
Test report here has no OCV3 Time column. This is different from report we get.
OCV3 Time really matters even though time value itself is not useful.
Column H?
Alkaline
Solar Wizard
280K is indeed a drama queen.
based on my research:
V1 280K around mid 280's real world test
V2 280K around upper 270's real world test
V3-R 280K with round base base mid 290's real world test
V3-O 280K with octagon base upper 300's real world test
I say this because when you test base on AH alone you will usually come 4-5 Ah lower than the spreadsheet, simply based on current. So a 313 will test to about 309.
EVE/SFK say you have to divide wh/3.2 to get match the label rating but that is another can of worms so we'll just stick to shunt amp measurements as its the most common method.
Notice: we are all bitching about a 280 cell not giving 300+. Truly spoiled we are
Brucey
Velcro Man
True, my understanding is that the actual capacity drops down after about 15-20 cycles anyway to a longer term trend
wfdTamar
New Member
My guess is that based on the round terminal base and the Ah result, the dual bolt ones in the SFK video are actually v.2 ones.
I was almost going to post that the OP's cells may not be v.3 until post #10 in the close up through the bolt holes it looks like the straight angled bit of the octagon (not round), so v.3.
As for the bitching about not getting 300+ - I see the stated capacity as a minimum (at least for 'Grade-A'). You would hope/expect a bit more. So for the 304Ah I've just received I'd hope for more. Maybe 310Ah+ (just testing the first now. Boy it takes ages with the little 20/5Amp tester).
I was almost going to post that the OP's cells may not be v.3 until post #10 in the close up through the bolt holes it looks like the straight angled bit of the octagon (not round), so v.3.
As for the bitching about not getting 300+ - I see the stated capacity as a minimum (at least for 'Grade-A'). You would hope/expect a bit more. So for the 304Ah I've just received I'd hope for more. Maybe 310Ah+ (just testing the first now. Boy it takes ages with the little 20/5Amp tester).
Alkaline
Solar Wizard
I think maybe the Dual Pole EVE cells are like Version 2.5 (basically a fixed version 2)
And the new ones with octagon base are Version 3
May be the EVE adapter doesn't fit the octagon so they are making both version 2.5 and version 3.
Again this is EVE and they never really tell the whole truth.
But either cells should more than easily hit its rated 280.
Lets assume they loose 20 AH on the top end, so a round base 300 will settle to like a 275-280 ish after the honey moon cycles
and the Octagon will be about 290 ish.
It comes down to if you want the eve terminal or if you want a little more capacity.
And the new ones with octagon base are Version 3
May be the EVE adapter doesn't fit the octagon so they are making both version 2.5 and version 3.
Again this is EVE and they never really tell the whole truth.
But either cells should more than easily hit its rated 280.
Lets assume they loose 20 AH on the top end, so a round base 300 will settle to like a 275-280 ish after the honey moon cycles
and the Octagon will be about 290 ish.
It comes down to if you want the eve terminal or if you want a little more capacity.
Spunky
Solar Enthusiast
Alkaline
Solar Wizard
Thanks for the pic/vid now we have no idea on what is really going on maybe someone from EVE will chime in.
wfdTamar
New Member
Just means the dual bolts doesn't determine the cells under it. I have them on Eve 304's.
Alkaline
Solar Wizard
You said OCV3 was missing I said look at column H.
OCV3 Time missing, not OCV3
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