Gobelpower EVE LF280K HSEV Cells. Perfect for DIY? All tests and what you need to know!

[@UnkyjoesPlayhouse]

I just finished combining my 2 24v DIY battteries that I built from watching you test each cell, balance, and then assemble with BMS and test, they are now 1 large 5kwh 48v battery. Just six more wires to hook up, bridge the two banks and bam we are online. Thanks for all your vids, been very happy following along.

[@OffGridGarageAustralia]

Thanks a lot for your feedback and getting inspired!

[@GregOnSummit]

Curious about your 24v batteries ... Are they 18650's or LifePo4 cells? I have a 5,040kw 24v pack made from 18650's using JAG HP PCBs. Wish I would have saved my money though, and gone with the LifePo4 cells

[@UnkyjoesPlayhouse]

They are LifePo4 cells, they work great, I followed along with Andy and thats how I built mine. @@GregOnSummit

[@universeisundernoobligatio3283]

Just got 8 EVE 280ah cell from Battery hookup. Shipped from the USofA to Canada in 5 days. So far they they physically look great, no swelling when they arrived, when charged very little swelling.Top charged and balanced, they came in very close. Did not bother with a capacity test, they are what they are. Adding to my solar system, built my own BMS with a Pic 18F4515 and a 18bit A/D MCP3424, want the engineering experience plus I get complete control of the software and A/D calibration.

[@SVAdAstra]

One of Andy's best videos where he points out a charge current cutoff at 0.05C. That's what most cell manufacturers specify. If you charge your cells to zero charge current and only detect the charge cutoff point by measuring cell voltage alone -- you are overcharging your cells -- causing lithium plating and cumulative capacity loss. Nothing practical is gained by charging beyond a tail current of 0.05C. I'm using Victron's Smart IP43 Charger that supports setting a tail current cutoff. It works well. The charger also integrates with Victron's smart shunt allowing for accurately detecting the battery charge current while ignoring any static load currents while charging.

[@OffGridGarageAustralia]

Very controversial topic. I know the graph from Nordkyn Design you are referring to, but there is no science behind it, so I doubt we are overcharging the cells. 0.05C cutoff is only valid at 0.5C charging current though.

[@GobelPowerBattery]

Hi Andy, It has been upgraded to flexible busbars for free now, the previous order was not.

[@JOHNDANIEL1]

I think I need to get some of your batteries to put on my YT channel for a high interest 12/36 volt system. Wind and solar hybrid.

[@thegolfhack9417]

@@JOHNDANIEL1 hahaha

[@thebeaglebeat3615]

Hello @GobelPowerBattery Is your website adding up the shipping correctly ? $1500 au for x8 280 ah batterys shipped to new zealand? Thank you

[@thebeaglebeat3615]

​@@JOHNDANIEL1 get kera on onto them

[@upnorthandpersonal]

Keep an eye on cell prices: they're dropping all over the place. EVE is selling 280k cells now at $71, and you can get cells already cheaper than that as well already. CATL predicts their cells to be around $50/kWh this year. Good times to build batteries!

[@andreasw5925]

True. Just ordered 32 eve lf280k v3 for less than 70$ Will buy more later this year 😅

[@ernestofs]

​@@andreasw5925where?😮

[@thegolfhack9417]

Where are you getting them

[@borichards978]

Where are you ordering these from? ​@@andreasw5925

[@mobilemechanix1]

Thanks!

[@FrancoP.G.]

Thanks for your test Andy! You are our North Star when it comes to the off grid world. Warm greetings from Sardinia!

[@OffGridGarageAustralia]

Thanks a lot, Franco.

[@MaximaleCoolness]

Evening Andy, just a quick note: your preferred voltages obviously depend on the discharging or charging currents. But whatever. I developed a selection method that showed me the problematic cells in my 4 16S packs before assembly. I bought 65 EVE280k last year, but unfortunately 2 of the cells are out of order. My plan is to charge all cells in packs of 16 to 3.65V, i.e. parallel top balancing, then disconnect the connection and compare the "cooled" voltage 2-3 hours later. In order to avoid errors due to different charging conditions and times, I then average each 16-pack and compare the voltage drop as a percentage of the pack's average. Two of the 65 cells stood out as particularly special. The range of the other cells was +5% to -5%. The two outliers had -20%. I selected the cells according to this table and installed them in my EEL boxes, one of the 20% remained. The other 20% (built into Pack4) still gives me problems loading the entire system. Packs 1 to 3 run smoothly, with small voltage differences, each as a separate system. Pack 4 is always so noticeable that I had to install an active balancer. So if you plan to build several packs, it is better to order at least 2 or more cells additionally and select all of them using this method and put the packs together that way. Maybe this will help someone. VG Jan

[@khalilullahyosufi9379]

Instead of order the 2 or more cells I prefer to use the JK BMS with 2 Amps active balance. The batteries will drift over the time without having the active balance.

[@OffGridGarageAustralia]

I never ordered any spare batteries. They will vary in capacity any way. If not now, at least in 5 years time they will... Charging to a specific voltage with different charge currents, there is an interesting video with test results on my channel: kzbin.info/www/bejne/p4vKZX2um9mqY8U

[@mikameikalainen2270]

Amazing video, once again Andy! These tests are absolutely brilliant. With the inspiration from your videos, I have also bought myself a small off grid system. I get to save money because of the up and down fluctuating electricity price. Greeting here from northern Finland.

[@OffGridGarageAustralia]

Thank you for your feedback. Do you charge of the grid when it is cheap and use the power when it is more expensive?

[@mikameikalainen2270]

Yeah. And now that spring is coming up north here, I think I'll buy a couple of solar panels to charge the batteries. The slope of the roof of my house is exactly towards the south, where the sun here shines the strongest. I already have victron 6000VA hybrid inverter with 450V/80A solar panel input. At this time I have two 14.4Kwh batteries (51.2V 280Ah with eve and rept cells)

[@markmark9532]

The service of Gobelpower is really good. I had a Problem with my cells and gobelpower reacted imediatelly and solved the problem! Now I have 4 complete 16s akkupack `s which are working perfect.

[@schunkelndedschunke6914]

You are right. I bought a 200A BMS to install it in my first 150A GobelPower battery. Gobel Power told me that I need two different metal plates for installation, so they sent me this 2 metal plates for free and the 2 power cables for the 200A BMS as well. Yesterday I got it. After the installation the 2 pcs 280Ah GobelPower batteries with the same 200A BMS should communicate.

[@OffGridGarageAustralia]

Great feedback, guys. That's always very good to hear!

[@TheEnteryourname]

So good! Thank you for the super informative videos and the accompanying graphics! Finally someone with a plan.

[@yooper423]

Another great video, Andy! Your explanation of the proper charge, discharge and balance voltage using the curves as a visual made so much sense. I am going to change the settings in my 4 DIY 280Ah batteries (EVE LF280K cells) in my RV to your recommended settings for charge/discharge/balance.

[@OffGridGarageAustralia]

Great, thank you. Also, if you don't use your batteries for a while, drop them even further down to say 60%SOC and disconnect them for storage. They will lose only 2% per month so will last a very long time without any maintenance.

[@AndreaFurlan-ro8cw]

Thank you Andy for all your work u doing for us!! U are a master on everything, and I really would like to meet you one time in my life! Good work Andy keep doing like this!

[@OffGridGarageAustralia]

Thank you very much for your kind words. Well, come over and say G'day when you are in the area.

[@AndreaFurlan-ro8cw]

@@OffGridGarageAustralia I’m actually in Italy but I used to live in Aussie land roughly 10 years ago (I miss that time) I was in Queensland like you, precisely in Bundaberg. Anyway I like you so much Andy, you are clever! Your channel has an awesome and simple way to explain things to people that others channels and KZbinrs have not! Can’t wait to see another video… Have a good one Andy, keep doing like this!

[@OffGridGarageAustralia]

​@@AndreaFurlan-ro8cw Thanks a lot for your king words. Ah, in Bundy... that a while to drive for me but I have been there twice.

[@thebeaglebeat3615]

Thanks!

[@OffGridGarageAustralia]

Thank you very much for your support🙏

[@FutureSystem738]

Thanks as always Andy. LOVE ❤️ your work.

[@OffGridGarageAustralia]

Thanks a lot Dave!

[@piotrs4618]

Dziękujemy.

[@OffGridGarageAustralia]

Thank you very much for your support🙏

[@michaelmurray9940]

Another great video Andy!

[@OffGridGarageAustralia]

Thank you.

[@mjp0815]

Beautifully explained the lifepo4 voltage kneeéey thanks!

[@OffGridGarageAustralia]

Thank you. Hope it all makes sense.

[@Dutch_off_grid_homesteading]

Heya, nice to see you testing battery cell's again. I'm almost ready testing my 16 cell's but they are not the 320AH as advertized I already mailed the seller and they told me to sent foto's or video to them to review so w'll see

[@OffGridGarageAustralia]

Where did you get them from?

[@Dutch_off_grid_homesteading]

@@OffGridGarageAustralia I got the from this seller PWOD Official Store

[@KevIsOffGrid]

I use 3v lower limit for the inverters, but allow DC loads to use down to 2.6 - lights, water pumps, internet, CCTV - the essentials :) And at the top, yeah, 3.45v is fine :)

[@OffGridGarageAustralia]

Yep, that's what I do as well. Works a treat.

[@2284esther]

Lol I do the same thing when going outside looking up to see if sun is shining. Production or maybe not! It's in God's hand anyway. Keep up the great content.

[@davidpenfold]

I tend to add a third part to my charge/discharge with the ZKEtech 40A tester, a CV 40A charge to 3.35V, with cutoff at 39.99A. This avoids having to do another full charge followed by a discharge with the smaller tester. It gets to about 30% SOC. It also means you get nearly three hours more sleep! Interestingly, my 304Ah QSO cells had an average discharge voltage of 3.25V.

[@OffGridGarageAustralia]

Charging to 3.35V does not really work as the cells will not absorb at this voltage. Current will go down very early and stop charging. We have tested this, remember?😉

[@davidpenfold]

@@OffGridGarageAustralia The point is just to hit a rough partial charge of around 30-35% after the full charge and then the discharge test as part of the same ZKETech configuration file so it's all done while you sleep! It's just to be able to put the tested cells back with the untested ones at about the same SOC. It's to avoid using your 5A charger in a separate process (or whatever weirdness it was, I can't really remember, i think it contained a slow full charge and some kind of approximate discharge). The voltage stays at 3.34 for a long time, in my experience (with 40A max, CV), allowing a pretty good charge that you can verify afterwards on your PC. Ah and W charge was always 30-35% for my 304Ah cells (actually I can't remember the exact range, maybe 35-40%, but it didn't vary much).

[@samsuffit6229]

Great video thank You for testing the cells from Gobel Power. I received my Gobel Power PC200 Premium Pack by middle of January 2024 (ordered End of November after seeing Your video with the NEEY 4A) and the cells look exactly like yours. The color of the base of the minus pole is grey/beige and the color of the base of the plus pole is black as yours. The cells are LF280K HSEV and the test date is 16.10.2023 and they were all tested with 314Ah and all with an internal resistance of 0.15 mOhm. There is no extra fuse anymore in my pack, all screws are firm and as I opened the case I discovered a long QC-sticker (Quality Check) handwritten with 15 checks! I retrieved the data for each cell using the QR code on the pack (only for the premium version). Unfortunately the pack was delivered with the old Heltek 5A without Bluetooth, but Gobel Power proposed two options: a financial reward or to send the NEEY 4A Bluetooth, which option I took. Glad to have Your video from November since I will have to install the NEEY 4A by myself ... (fühle mich nicht wohl dabei ...) great exercise for building my own one later this year based on those Gobel Power cells and a EEL V4 case ! Thank You so much Andy ;-)

[@OffGridGarageAustralia]

Thanks a lot for sharing. Be a bit careful with replacing the active balancer. It might be easier to leave the old one just in the case and disconnect it and install the NEEY somewhere else in the box. That is way easier and safer.

[@gio.9129]

hi, the coupon for the gobel site only works for the bms, it does not apply to batteries.

[@ingo3129]

Hallo Andy wieder ein sehr interessantes Vido mit vielen Informationen. Schöne Grüße aus Kassel

[@OffGridGarageAustralia]

Dank Dir Ingo. Gruesse ins Ahle Nest!

[@amilww]

Awesome Andy (as usual)!

[@OffGridGarageAustralia]

Thank you.

[@hervehum6454]

Thank you for your advice. in my case, I already have 8 cells in service but grade B or LSEV from Gobel. I'm thinking of putting them in parallel with 8 other cells but grade A or Hsev, still from Gobel. Normally, it is not recommended to combine two battery packs of different wear and quality (identical capacity and brand), but my reasoning is that it is not a question of increasing the charge (which will remain at maximum 0.5 c see very exceptionally above), but the energy reserve. So, the principle is to say "who can do the most (grade A) saves doing less (grade B will be less requested and will save A). But maybe my reasoning doesn't hold up? What do you think ?

[@jawata58]

Hey,I try to download the data of the Globel stud 304Ah, but there is a problem, dropbox says"that didn't work for some reason" An idea why I cannot download them from dropbox? I have the same cells! very good quality.

[@mattr8202]

Hey Andy I’ve watched your channel since day dot, love the battery testing still don’t know why haha. But I just wish you weighed all of these cells on an accurate scales to add to the data set

[@OffGridGarageAustralia]

I guess that's a joke, right😆

[@davidpatrick1813]

Do the battery bank (12, 24 or 48) of lithium iron phosphate make a "memory" at discharge and charge ... ? The point is I don't discharge them from near full down to 50% ... I use Victron and of course the smart shunt. I set the 100 to show or leave about 10% in the bank... which I may have never seen ... I wonder how deep and how often I might discharge the bank ... if it will effect the life span ... good bad or indifferently. pat

[@michagooglein5008]

fine new eyeglasses, dear Andy.- You look very stylish!

[@OffGridGarageAustralia]

Just for computer work. Got them for years, so they are old😉

[@danfitzpatrick4112]

Very interesting test and comparisons!

[@OffGridGarageAustralia]

Thanks, Dan.

[@loucinci3922]

Enjoyed the video. Thanks for sharing

[@OffGridGarageAustralia]

Thanks for watching

[@michaelfleming8454]

Love your work Andy, and please pass on my appreciation for Andy 2 also (Haven't seen him in a while, I hope he is OK). I really was impressed with this video and the LF280K cells from Gobelpower, so I just had to order some for myself. I have had a 4-8S JK BMS sitting around for a while now that needed some love. I am stoked with the battery that I have built, but noticed some strange occurrences that you may be interested in. Firstly, if I turn off the Charge Mosfets (Leaving the Discharge Mosfets on, with no load), the measurable voltage drops around 500mV from 13.3V to 12.8V. Have you ever seen this? I have not seen this phenomenon in any of your videos. Secondly, with a 3000w inverter connected, If the Discharge Mosfets are turned off (via the app control and regardless of the Charge Mosfets state), the BMS has Discharge Short Circuit Protection and cannot recover until inverter is disconnected. Again, I have never seen this scenario in your videos, it is usually the inverter that shuts down due to low voltage before the BMS does. Forums cover issues relating to the inrush current (charging the inverter caps) and settings that can rectify the Discharge Overcurrent Protection, but I have found nothing about the inverter causing Discharge Short Circuit Protection. I would love to know your thoughts, and does anyone else have these issues? Or is it just me, am I doing something wrong? Will this never happen in real-world situation and I should just simply avoid turning off Discharge? Should I be using a diode or a disconnect switch as protection? Back on a happy note to finish off. The LF280K cells from Gobelpower were amazingly matched, the BMS has not shown a variation of cell voltage above 5mV even when charging or discharging with 20A. I haven't managed a full charge to 100% yet due to the mushy weather in Brisbane yesterday and for the next few days. My 900W solar array managed about 550Wh yesterday from 11am to sundown (only 3.0 amps outside). Apologies for the lengthy comment and questions, I would love to know what you and the community think about my issues.

[@GarryL277]

I have the Gotion 340Ah cells but unable to test them but they do last a long time.

[@richardbryan2376]

Andy Just a quick question, I have 32 280 ah cells and just bought the ZKE EBC A 40L charger, can I hook the all up in parallel and top balance them all at one time. I am now trying to charge 8 cells with a small 5 amp charger and it was taking months to charge them. I would rather charge them 8 at a time as I will be making 4-24 volt batteries to go into my RV. Thanks you Richard

[@errcl65]

What are your new bulk charge and float charge voltages for the Victron?

[@betterlifeacademy1744]

Would be Nice to see the resistance of the cells. Because in the past i have made experiences that B grade have many different resistances and A grade cells have really good ones. All around 0.18 in my läßt batch

[@kevinmills5293]

I’ve just built a 15kWh battery using ESS grade B cells. They arrived in perfect condition and with a delta V of 5mV. IR ranged from 0.19mOhms and 0.21mOhmes. They have been in service only a week but so far they seem very good.

[@OffGridGarageAustralia]

I tested A again B grade cells many times and never could find a difference in internal resistance. All this Ri, voltage and capacity matching is just a marketing trick from the suppliers. It's a snapshot at this point of time as I explained in the video.

[@ericklein5097]

Re: Discharging to only 3.00V or 3.10V...keep in mind this is with a 40A discharge current which is relatively weak. In a 51.2V battery it would be ~2kw so maybe a normal load....but if you're doing a 12V battery that's pretty much 500W... So it really depends on what kind of current you are pulling. If you're pulling 100A from the battery expect to see a pretty significant difference in voltage drop especially as you get closer to 3.00V Would be interesting to see what the voltage is at 95% DOD for 10A, 20A, 40A, 50A, 100A, 150A, 200A, and 250A. I think that covers most of the BMS's on the market that you would likely be using. I'd guess that 100A would be closer to 3.00V for 95% DOD, 200A would probably take it down towards 2.85V and 250A would probably take it down to 2.70V? Those currents above 100A are really going to depend on your cells DC IR...so any set of data you see on this cannot be applied to your pack unless you happen to have cells that match the DC IR of the cells being tested....and testing LifePO4 DC IR is kinda...difficult since the curve is so flat....a linear curve makes DC IR a lot more meaningful

[@iviemaro380]

Hi Andy! How much did gobel power charge for shipping your 16 cells? I’m not sure if their website is adding up correctly via shipping. They are charging $2010 just to ship 16cells 280ah to Africa please it’s this normal?

[@douglasmarquis3446]

New glasses at the end of the video? As always great information.

[@OffGridGarageAustralia]

2nd pair for close distance. Working better with the computer🤓

[@douglasmarquis3446]

I have the same problem, two pairs of glasses. It is hell getting old ,will be 70 in a few days. I enjoy your channel.@@OffGridGarageAustralia

[@SandeepSingh-ht3ug]

Seplos Mason 280L next video? Cant wait!

[@OffGridGarageAustralia]

Coming tomorrow!

[@SandeepSingh-ht3ug]

@OffGridGarageAustralia I'll be watching first thing in morning. I received my Mason 280L 3.0Y with active balancer, all looks good including flexible busbars etc.. but I'm missing 4 or 16 cells which were lost in transit.

[@paulg1802]

Finally commissioned 5 280AH battery packs. all with your least favourite 300Am Daly BMS with parallel communication boards but had to get firmware to enable cumulative current limit communicated to DEYE inverter..

[@OffGridGarageAustralia]

I still have the Daly BMS with coms board and parallel modules here for testing. They dropped the coms a bit on that, so not sure if I want to proceed with promoting their stuff.

[@paulg1802]

@@OffGridGarageAustralia am sure it will make you mad as it is no where near jk BMS. but when you need that high current discharge, it's the only option.. it like that old Toyota it gets you there with nothing much to say about it.

[@nobuookumura5742]

I'm currently using two battery banks: an EVE LF280K and a B grade cell without a QR code. Considering the situation, isn't it bad to compare charging power and discharging power? I feel that the difference between B-grade cells and A-grade cells is not only in capacity, but also in charging efficiency. B grade cells have large irreversible changes such as heat generation and internal pressure increase during charging, which seems to cause a decrease in efficiency. I would be happy if you could verify the charging efficiency once.

[@OffGridGarageAustralia]

I have A, B and other cells in parallel for years, there is no problem if they have their own BMS and breaker. The cells will charge and discharge to their best capability. I have done may tests here with A and B grade cells and could never really find a difference in efficiency. If you would not know it's a B grade cell, they work perfectly fine without issues, same as certified cells.

[@nobuookumura5742]

I haven't had any problems with operation either. But I have doubts about efficiency. Normally, even if the BMS indicates that the SOC has returned to 100%, the battery terminal voltage will not reach the full charge voltage and additional charging will be required to account for the inefficiency of charging and discharging. While this additional charge is less than 10AH for EVE, it can exceed 30AH for B grade cells. These cells of mine may not be B grade, but may be worse products.

[@USL.Website]

Great info!! Thank You, Andy!! 👊

[@OffGridGarageAustralia]

Thank you.

[@MMMM2MMMM2MMMM]

Would a bi-facial panel mounted verticale and placed East-South make any sense? I was thinking of building a fence that could be beneficial.

[@OffGridGarageAustralia]

What about the wind load?

[@DanBurgaud]

BTW. Sodium Batteries are now available... What do you think? Worth the test? I read that the voltage vs SOC% is not as flat.

[@OffGridGarageAustralia]

I have a few here and will test them soon.

[@DanBurgaud]

@@OffGridGarageAustralia will wait for your objective test!

[@fldutch]

I like cell testing videos :) Thx. On the 0.05C / 14A cut-off: this is meant for 0.5C (140A) charge. So i'm not sure if this is also applicable for charging with 40A only. I would still use 0.1A (there has been some discussion about this in the akkudoktor-forum in germany not to do so), since i tested all my cells this way - but also would not recommend this to others ;). If you take the same ratio cut-off to charge current like in the EVE datasheet, you could go for 40A charge current and 4A cut-off (10% of charge current)? The main argument for working with a higher cut off is that Li-Ions struggle to integrate into the grid structure (on a molecular level) at the end of the charging process (because the grid is near to saturation), causing sth. non reversible like Li-plating inhibiting the grid structures (on a microscopic level) - so when repeating this too often you might get lower cell capacities... As far as i got that right. So when you reduce the cut-off current the probabilty of Li-plating will be highly reduced. Haven't seen any scientific publication on this, just some theoretical thoughts on this. Maybe the 0.05C cut-off is just about time economy, because a lower cut-off really takes more time. The result does not change as much. In a productive enviroment it's of course sth. totally different ;). On the reproducability of testing: when you compare to the factory test, yes, it is not the same. My findings: when i test one cell and do a retest some days later (same temperature!), that cell shows the same behavior in the curve and also nearly the same capacity. So why it might be important to test cells: well, when it comes to trustable HSEV or "Grade A" or "Automotive Grade" cells, you could skip testing - just do a top-level balancing and that's it. When it comes to not 100% trustable sources, i would recommend testing cells - just to check if there are any real bad cells in the batch. But also: i have not found any results in capacity or cell resistance indicating the behaviour in the productive enviroment. I tested one EVE LF280K v3 Grade B cell with a strange discharge curve (voltage dropping, shortly rising and dropping again) which goes "off" above 3.4v quicker then the rest. The discharge curve could be repeated 4 day later. Since this behavior occured below 2.9v i did not care and kept the cell (even though the supplier offered me to return it) - but it's under close monitoring, too curios how this cell will behave in the future. Thx for stating the importance of matching the curves! I really do appreciate Gobelpower does this. On the curve comparions Gobelpower vs EVE "Automotive Grade" - the cells you tested from Gobelpower are already v3 of the EVE LF280k seeming to be improved (you can tell this from the hex-shaped terminals). Furthermore i did a comparison of standard deviation in tested capacity of 3 different 8 cell batches i ordered (all EVE LF280K "Grade A" v2, Automotive Grade Cells v2, Grade B v3). The automotive grade cells are much more closer together in cell capacity testing. But my monitoring also shows that this does not reflect on standard deviation of cell voltage in the productive enviroment. So i do like testing cells (and will do so with upcoming batches) and also identified a "bad cell" candidate - but my findings show: it might not be necessary at all, when you find a supplier that delivers good quality cells.

[@OffGridGarageAustralia]

Yep, I know this discussion very well. I think we will have this on one of our next live streams on Meine Energiewende.

[@markhamilton6065]

Rain is good - cleans the dust off the panels. And it cools you down.

[@OffGridGarageAustralia]

I never cleaned these panels sind installation and still have full power output when the sun is out. I think it's more us because we like clean things😄

[@rcinfla9017]

RECORD the cell ambient temperature when you make tests!!!. Overpotential voltage slump at a given load current is dependent on cell temperature. Another good thing to do is to install EB40 sequences at approximately 75%, 50%, and 25% SoC to allow 5 minutes of zero load current, then pick up 40A discharge again. The five minute rest will allow cell to recover to rested unloaded state so you can measure overpotential voltage at the 40A load and 40A charging. Knowing the overpotential voltage is as important as the knowing the capacity. Larger overpotential is a weaker cell. Overpotential increases as cell ages. If you do 40A discharge immediately followed by 40A recharge, half way between the charge and discharge curves is roughly the cell overpotential at 40A and a curve drawn half way between the charge and discharge is the open circuit rested cell voltage vs SoC.. LFP charge and discharge overpotential voltage is fairly symmetrical (close to the same overpotential voltage vs current, just pos for charging and negative for discharging,) If you do the 5 minute rest period the rest voltage recovery should come to that mid-line between the discharge and recharge curves. Truly matched cells have the same overpotential voltage slump for same discharge current (at nearly same ambient temp) as well as same total AH capacity.

[@OffGridGarageAustralia]

Ambient temperature never made a huge difference when testing in my garage. if 15deg or 30deg, no difference in capacity I could measure... I cannot change the test procedure any more to allow for pauses while testing, that would destroy the curves and makle them not comparable any more. And, honestly, this is not how the cells are being used in practice any way. I know EVE does that similar things in their test procedure and add these numbers in their spreadsheet.

[@GregOnSummit]

I see a lot of these newer 280AH batteries giving 305+ AH. So if you set you battery size to 28OAH, but the cells are actually putting out 305AH or more, aren't you losing usable capacity? Would it be worth setting the actual battery size to the lowest tested capacity ... like 305AH if the tested range was from 305 - 309AH, even though they are listed as 280AH cells? One other thing ... I thought you used to say to charge to 3.65v, float for a few hours for absorption, then drop down to 3.45v? Are you saying that a charge to 3.65v is not necessary? I get the idea of just charging to 3.45v, float, then drop to 3.35v, which is the natural voltage of the cells. With that in mind, would it be worth charging to the higher voltage, 3.65v, from time to time and doing a good top balance. Maybe treat it as an equalization voltage charge? Anyway ... another great video that has my mind spinning ...👍

[@OffGridGarageAustralia]

You can set the true capacity in your inverter or shunt so it measures correctly. NOOO, I never charge to 3.65V and hold the voltage there. NEVER! Charge to 3.45V, hold there for 30min to give the balancer time and then drop to 3.35V. That's it. 3.65V is the maximum voltage you can charge the cell to but as you have seen, charging to 3.45V is already 99.3%SOC.

[@EricZuber-z6l]

good stuff and well done. Tnx

[@OffGridGarageAustralia]

Much appreciated!

[@wenhaowong5549]

Just wonder when doing discharge test will the different ambient temperature give huge different results?

[@OffGridGarageAustralia]

Not a few degrees, no. If you have like 20deg difference, there will be difference but not by much.

[@typxxilps]

Unfortunatelly I had 1 bad cell among 16 and the likelihood to miss that not so nice one was too high so I checked them all - 3 times in a row with 2 of these blue big chargers / dischargers Have you checked the last charge to 18A or 26A cut off current ? We have seen quite different amount of energy charged till cut off. 33% difference between the lowest and highest charge amount.

[@OffGridGarageAustralia]

What do you mean by 'bad cell'?

[@anthonyrstrawbridge]

Guten Tag, Herr Andy The mass difference between a charged and a drained battery cell varies depending on the type and size of the battery. However, on average, a charged battery will weigh slightly more than a drained battery .

[@OffGridGarageAustralia]

Did you read this somewhere or tested yourself?

[@anthonyrstrawbridge]

@@OffGridGarageAustralia Ya! I measure the gravity of both batteries and my wort using a hydrometer. As the electrolyte or wort load up with solids like electrons or sugars the hydrometer floats higher on top conversely when discharge electrons or ferment sugar to alcohol the hydrometer submerges into the electrolyte and alcohol water. The density increase of lithium is more extreme that's why they ship em light.

[@shugshyam4701]

First of all thanks so much for your enthusiastic work! We are 100% Off grid and just now switched from lead acids to lifepo4. Do you do consultations by chance? We have some questions we would love to ask you Thanks so much for all that you do! Shug

[@OffGridGarageAustralia]

Thank for your feedback. Sorry, I cannot do any consultations for legal reason and also not being familiar with all regulations around the globe. You can always leave questions under the videos and I will answer them there.

[@Juergen_Miessmer]

Gobel sells 280 Ah 'Battero Tech' grade ESS cells for around 50 bucks. Has anyone got them and tested ?

[@OffGridGarageAustralia]

I'll see if I can get some to test. Price sound too good...

[@darrenfrater3496]

Yes i was thinking the same

[@Juergen_Miessmer]

@@OffGridGarageAustralia Gobel says they are OK. But they were sitting in a stock for a a bit more than year, this is why they sell them at that low price - a remaining stock sale. They also equip their 'Basic' version batterybox with this cells.

[@wayne8113]

Thanks Andy

[@OffGridGarageAustralia]

Thanks Wayne!

[@iaandewet9778]

Might have missed it but what would be the number of cells to be tested per 16 cells bought at the same time ? Testing all 16 will take a long time. Love the videos

[@OffGridGarageAustralia]

I would not bother testing any cells at all if it would not be for the channel. Just put them in series and charge them.

[@spicy0076]

Hi Andy i follow your video about JK BMS and the setup, i change the discharge OTP temp to 60 deg cel and when i used it reach almost 70 deg and i got warning in the bms, the motor still running and everthing was fine. But after that i notice the discharge on off option is not working, i can still run my motor eventhoght the discharge is off. Do you have experience with this, please help?

[@OffGridGarageAustralia]

Where do you measure the temperature?

[@spicy0076]

@@OffGridGarageAustralia i got the number from the moss temperature in the bms. Recently it says Discharged moss abnormal. I notice the moss tempature increased evertime i turn on the discharged even there is no load. Is there something wrong with the discharge mossfet? Do you have suggestion how to check?

[@JOHNDANIEL1]

I have interest in checking out your source. Not sure if they deal with USA stock. I have great luck with Lishen cells that came from Gobel.

[@OffGridGarageAustralia]

Gobel has got a warehouse in the US afaik so should be no problem.

[@theacme3]

Hey, off topic but: Why is there no "fireware" updates for the JK BMS (PBA2S16P15/20) for the 15.xl hardware? The 14.xl has software update 14.20 now but the 15 is still on 15.10. I cant find anything on JKs homepage as the download links removed. Is 15.10 the newest version? (my bms came with 15.10). The communication is really bad for JK ;-(

[@OffGridGarageAustralia]

14.20 = 15.10 Only JK knows why they have 10 digits in between the versions of these BMSes China is celebrating the New Year atm, no communication before 30th Feb.

[@OOTBWindsor]

Speaking of BMS's for 16S LIFEPO4 batteries, do any of the BMS manufacturers you have dealt with produce a 16S LIFEPO4 BMS that is capable of being connected in series for nominal 96V (102.4V) at 200A-300A maximum continuous current draw? I have come across a JBD-AP21S002 but the spec sheet is confusing. It says series is not supported but yet has a note that says "The battery pack can be used in series, but the total number of strings after series is required to be less than or equal to 32" . Can you offer any advice on this?

[@OOTBWindsor]

Does JK have a 16S BMS that supports connecting 2 banks in series for 96V? Thanks.

[@OffGridGarageAustralia]

I really don't know. 96V is out of specs for DIY and there is almost no equipment out there to connect to such a battery.

[@OOTBWindsor]

@@OffGridGarageAustralia Thanks for the reply. It actually will only be running 48V loads. It is an experiment on energy recovery that in theory requires 2 48V batteries to be connected in series for a short while. Should one of the BMS's go into protection mode for whatever reason, the other needs to be able to withstand the full 96V without killing the bms. It would be nice to know specs of the mosfets used in the 48v BMS's. Thanks for the vids. Very interesting content.

[@diysolaradventures7894]

I'm wondering why my cells deviate so much from each other when charging does it effect the capacity of the cells ?

[@OffGridGarageAustralia]

More details needed.

[@diysolaradventures7894]

@OffGridGarageAustralia I have 8 280ah cells not sure of manufacturer on a 24v solar system using a Daly Bluetooth bms the balance does seem to be on but these cells seem to go way above 100 to 200 deviation in milivolts when charging the Daly bms seems to push the high voltage down I'm just wondering is it enough

[@Oli83two]

Ich muss das jetzt mal auf deutsch schreiben: meine 16 EVE lf280k Zellen sind von gobel aus 2021 und 2022. Inbetriebnahme Oktober 2022. 4 Zellen verhalten sich anders als die anderen. Sie rennen zuerst hoch bei 98% (3,45v+) und sind zuerst leer (unter 3,1v) gekauft habe ich damals noch die gradeA HSEV, welche mit 280Ah angeboten wurden, "matched in voltage and capacity"... macht das Sinn diese 4 Zellen nach über einem Jahr Betrieb (115cycles) noch zu reklamieren? Bis auf deviation von 50-100mV bei voll und leer habe ich keine Probleme! 😮 Ich würde mich total über einen Tipp von dir freuen! Viele Grüße aus Germany 🙃

[@OffGridGarageAustralia]

Miss doch mal die Kapazitaet von einer guten und schlechten Zelle. Dann hast Du was in der Hand. Musst halt die Batterie solange still legen.

[@burnzy56469]

Hi Andy and group members do you guys know if Andy has a Diagram of his solar panel set up. How many panels on each roof.

[@OffGridGarageAustralia]

Yes, there are videos here on the channel explaining this in all details. Here is the playlist: kzbin.info/aero/PLPomydD54sgDVbyGpvYOHYLSVg1e663Sj

[@burnzy56469]

@@OffGridGarageAustralia thanks andy

[@salarhadi2988]

Thank you Andy for explaining but keep eye on cells price is now dropping in markets

[@OffGridGarageAustralia]

Prices are always changing. You buy when you need them...

[@Slavomir-1977]

Hi Andy .... As always a super video. I would have a question. I noticed at the bottom of the VRM temperature. What sensors do you use and how and where did you connect them? You could make a short video about it. well thank you

[@OffGridGarageAustralia]

Thank you. I made a video about the sensors here: watch from 11:45 kzbin.info/www/bejne/i3fJpJyCntitn7c Or here: watch from 16:00 kzbin.info/www/bejne/oXK3ZoF6rtyarc0

[@netrocker9990]

Ev grade cells are manufactured by keeping target of handling huge charge and discharge current,not only for more capacity

[@andreasw5925]

That was also tested on this channel before and was not confirmed at least with this specific test and environment

[@OffGridGarageAustralia]

Correct, certified automotive grade cells had no advantage over so called B-grade cells from my test results. kzbin.info/www/bejne/bIHccoGQjNl-pLs

[@mariapanni8112]

Hallo Andy, ich habe genau diese Zelle im Januar bestellt und sind unterwegs, vielen Danke fürs Video. Wollte ich Dir fragen ob ich den Kapazitätstest machen muss ( hab das gerät nicht) oder kann ich direkt top balancieren? Sorry kann ich nicht richtig englisch

[@OffGridGarageAustralia]

Must Du keinen Test machen, einfach all in Reihe schalten udn aufladen. Lass das BMS das Top Balancing machen. Fertig!

[@mariapanni8112]

@@OffGridGarageAustralia Vielen Danke Andy LG

[@Theo-dq6rq]

@@OffGridGarageAustralia Hello Andy, I also ordered the same cells, together with a jk-bms. Do I understand it correctly? Connecting the cells in parallel and top balance them at 3,65v (as is often strongly advised) is not really necessary. Or in case you still would want to do so, top balancing to 3,45v in parallel would be enough. The cells would reach 99,3% Soc without any stress. The BMS then will balance them out after being connected in Reihe.

[@cafecomsolar]

Muito bonita essas baterias 280 EVE,,,, parabéns pelo teste,,,,

[@miniwindow]

Thanks for the video. I request you to make a video 20A cell with 40A charging current and test its AH capacity

[@OffGridGarageAustralia]

What is a 20A cell? A 20Ah cell? Why would you use 2C for charging? This is way out of the specifications of most cells...

[@christophec252]

Something you can tell us: do you think with a new battery pack the best is to charge them in parallel with a charger or better with inverter and stay balanced ? Any differences? And last important thing. Nice new glasses 👓 😊

[@OffGridGarageAustralia]

If you use a JK BMS with active balancer, you don't need to charge them in parallel any more. The BSM will do the rest for your. I will show this in the video after the next one.

[@michaelcoghlan9124]

Thank you very much. M

[@pmacgowan]

Thanks. Andy :-)

[@thebeaglebeat3615]

Just went on the gobel power website to order batterys & shipping is $1500 for x8 280 ah batteries to new zealand!! How much did you pay Andy?

[@OffGridGarageAustralia]

Get in contact with them to confirm shipping cost. Their shipping calculator is not accurate sometimes.

[@darrenfrater3496]

I ordered and paid for these cells and was told after that i need to pay extra for shipping, i an now changing my order to for better value on shipping, i will update once i test all cells. Keep up the good work Andy.

[@TheMartinmy]

Is EVE now using different terminals / electrodes? If you look closely these are almost Square with cut corners, but EVE usually has circular ones with specific shape palstic. Are these even EVE cells? Edit: Got info that this is new version of EVE terminal.

[@OffGridGarageAustralia]

Yes, that is the V3 of their LF280K cells with the hexagonal terminals. I forgot to mention that. Latest and greatest apparently, maybe even a bit different goop inside?!

[@AlexanderBelikov]

Was the environment conditions the same when certified cell was tested? Wondering if much hotter or cooler temperature could move it's line. Or it just such a cell indeed. Great video, Andy!

[@OffGridGarageAustralia]

That's exactly what I said. Don't give anything about Ri, voltage and capacity tested. That was a snapshot the supplier/manufacturer did. So ,your experience can be wildly different.

[@rogereldridge8233]

I just got a shipment of 32 280 Ah cells from WeberPowerTech and have started testing ... so far all at 302 Ah (mine came with nice flexible busbars). After a bit more testing I'll be assembling them into battery boxes in 2p8s config (for my 24v system) with the new JK Inverter BMSs using the JK 4.3" screens. Did you get your screens yet Andy ?

[@anthonyrstrawbridge]

Wow! Ist das flexible ones tinned copper?

[@nigelcharles511]

I seem to remember you used to leave a 30 minute rest window for the cell to settle down before commencing the discharge. Is this deemed to be no longer required?

[@OffGridGarageAustralia]

This is only what the manufacturer does to harmonise their testing. We can do whatever we want... It was never a requirement though.

[@davidkarlas7476]

Any plans to test some Sodium batteries? I understand they have different voltage voltage from rest of your batteries but in theory should be much cheaper in few years.

[@OffGridGarageAustralia]

Yes, got some here already and will test them soon. They won't be cheaper ever, is my expectation.

[@davidkarlas7476]

I hope you cover that theory about price in video aswell :) Is it because scale of mass production, manufacturing process or some other reason?

[@jonaslundqvist9605]

Have someone tried the Battero Tech 280ah cells that gobelpower sell?

[@OffGridGarageAustralia]

You mean Battero Tech BT280?

[@jonaslundqvist9605]

​@@OffGridGarageAustraliaexactly

[@thestoicloner]

Andy you could open a energy company with all these batteries

[@OffGridGarageAustralia]

I can stabilise the whole grid here on the island😆

[@thestoicloner]

@@OffGridGarageAustralia 😆

[@completelyrandom4060]

been watching you for long time now. have you tested hakadi battery love some input on them

[@OffGridGarageAustralia]

Thank you. Never heard about these batteries.

[@matthewknight5641]

Thanks for something other than all the inverter jk BMS stuff. Love the channel tho lol

[@OffGridGarageAustralia]

Thanks, something for everyone😉

[@energietechnik4138]

Grüße Andy, du sag mal im letzten coolen Livestream sah man von deinem 2.Buddy ein Fronius Gen24 Primo, hast du den am AC Out des MP2 gekoppelt im Fronius MG50 Modus? Danke dir schonmal Gruß Daniel

[@OffGridGarageAustralia]

They are separate systems. The Fronius is still grid connected but will be connect to the Multi AC-Out in 2028.

[@OrganicPower-Australia]

Another great vid but... This is a lot of work, we used batts with internal BMS and equalisers. Cost effective and super easy to build. Internal Bluetooth would have been nicer but the cost was a fair bit higher. Let me know what you think cheers @OrganicPower-Australia 😎

[@MaximaleCoolness]

Nabend Andy, erst ein kleiner Hinweis, deine bevorzugten Spannungen sind natürlich abhängig von den Ent- oder Ladeströmen. Aber egal. Ich habe eine Selektionsmethode entwickelt, die mir vor dem Zusammenbau schon die problematischen Zellen meiner 4 16S Packs zeigte. Ich habe letztes Jahr 65 EVE280k gekauft, aber leider fallen 2 der Zellen aus dem Rahmen. Mein Plan ist, alle Zellen in 16er Packs auf die 3,65V zu laden, also paralleles Topbalancing, die Verbindung dann zu trennen und 2-3h danach die "abgekühlte" Spannung zu vergleichen. Um einen Fehler durch unterschiedliche Ladeverhältnisse und Zeiten rauszuhalten bilde ich dann von jedem 16er-Verbund den Durchschnitt und vergleiche die prozentual zum Durchschnitt des Packs abgesunkene Spannung. Dabei traten 2 der 65 Zellen als besonders hervor. Der Bereich der anderen Zellen lag bei +5% bis -5%. Die Beiden Ausreißer hatten -20%. Ich habe die Zellen nach dieser Tabelle selektiert und in meine EEL-Boxen eingebaut, eine der 20%er blieb übrig. Die andere 20%er (eingebaut in Pack4) macht mir bis heute Probleme beim Laden der gesamten Anlage. Pack 1 bis 3 laufen problemlos, mit geringen Spannungsdifferenzen, jeder als eigenes System. Pack 4 ist immer so auffällig dass ich einen aktiven Balancer einbauen musste. Wenn man also vor hat mehrere Packs zu bauen, besser min 2 Zellen zusätzlich bestellen und Alle nach dieser Methode selektieren und die Packs so zusammenstellen. Vielleicht hilft das jemandem. VG Jan

[@OffGridGarageAustralia]

Well, they are not actually. It depends on the absorption time you allow at this specific voltage. Here is the video I made a while back about it: kzbin.info/www/bejne/p4vKZX2um9mqY8U

[@joesmith1142]

Those must be the cells in my E-Poch 300 Ah V2 battery. I know they are using the EVE cells. The complete 12 volt battery is 4s1p and tested to 316 Ah's. Oh! maybe not ha!...I should have watched to the end of video before commenting...didnt realize there was an EVE 304 Ah cell.

[@OffGridGarageAustralia]

Yeah, most likely they used 304Ah cells for your battery and rated it at 300Ah. That's actually a good move from them.

[@Jonyys]

👍👍👍

[@clarencewiles963]

So I see it not worth going to a grade A versus a grade B. They are just fine. The manufacturers are still adjusting their base as well. Understandable 😊

[@SandeepSingh-ht3ug]

I think all EVE with octagon terminals are V3 batteries which have >6000 cycles and claimed to have ~300ah actual capacity.

[@OffGridGarageAustralia]

Yes, these are the V3 of the LF280K cells. I've forgotten to mention that.

[@swolath]

HOW MUCH DID YOU PAY FOR SHIPPING

[@OffGridGarageAustralia]

You have to negotiate. I got some other stuff as well, so can't really say how much it was just for the cells.

[@AlsinoFerreira]

😎

[@paulcurtis5496]

Like# 1 - You make me want to build a battery…

[@OffGridGarageAustralia]

Great second place, Paul! 🥈

[@opless]

First!!!!❤❤❤❤

[@OffGridGarageAustralia]

You are! 🥇

[@johntheaccountant5594]

You do not sound very Australian. You have a German accent. I have learned quite a lot from this but not sure if it is all necessary.

[@OffGridGarageAustralia]

As long as you have learned something, that's great!

[@sjsmith801]

Thanks as always for your fantastic and detailed content. A question if anyone can answer it, can these prismatic lifepo4 cells be installed on their sides, and stacked on each other? It seems to me that I've seen them on their sides and stacked pretty frequently in your videos, but I see conflicting info about that. Folks will say the safety vents need to be upright, or the electrolyte will be distributed wrong, yet then others will say there is no liquid electrolyte in these battery cells. Maybe @gobelpowerbattery can help answer. I have their cheaper "Battero" cells, if that matters. I'd like to stack them on their sides, 3x high in multiple rows.

[@dredre9484]

G'day mate can you do a reviving a lithium iron battery I know what to do it's very easy but it would make a good video mine went to sleep no use for two years but a simple trick you can bring them back to life(sorry leaded battery your such old technology) have fun people

[@OffGridGarageAustralia]

Well, if you know what to do, why not putting out a video on your channel and we all come over and watch it there?😉 I don't have any dead batteries here...

[@GeraldKnotzer-cq1ix]

hallo teste doch einmal 300Ah Winston zellen das wäre toll

[@OffGridGarageAustralia]

Schick mir welche. DAS ware toll 😉

[@icu9916]

Mist. Habe da im November 280ah EVE cells grade B bestellt. 70 Euro das Stück, dachte das sei billig. Mit Steuern und Transport nach Deutschland habe ich für 16 Stück 1474 Euro netto bezahlt. 6 Wochen nach der Bestellung waren sie da. Alle Zellen sehen gut aus, tun was sie sollen und waren kein bisschen bauchig. Aber der originale Barcode war weggeschliffen und durch einen von Gobel ersetzt. Bis gerade war ich noch sehr zufrieden mit meinem Kauf.........

[@mariapanni8112]

Hi, ich habe vor paar Wochen 16 Eve HSEV Grade A bestellt für 1365 ca. mit Versand

[@icu9916]

@@mariapanni8112 Auch bei Gobel Power? Ich bin schon mal auf die Schnauze gefallen mit einem "Super Angebot". Am Ende wollte der Verkäufer in China mich reinlegen und hat behauptet, die Pakete wären von mir nicht angenommen worden... Ich hatte Glück das Aliexpress mir das Geld zurück erstattet hat. Ich denke das die Preise generell weiter fallen werden, wegen der kommenden Natriumzellentechnologie.

[@Juergen_Miessmer]

Tröste Dich....ich habe vor gut einem Jahr bestellt und will gar nicht mehr wissen, was das da gekostet hat, sonst bekomm ich die Krise... Die Preise sind mächtig gefallen.

[@OffGridGarageAustralia]

Preise gehen rauf und runter. Man kauft, wenn man die Zellen braucht, warten macht keinen Sinn. Ich hatte auch erst B-Zellen im Warenkorb aber Gobel hat mir da ein gutes Angebot gemacht... Ich wurde immer nur B-Zellen kaufen, wenn die billiger sind.

[@icu9916]

@@OffGridGarageAustralia Die haben auch noch billigere Zellen, für knapp über 50 Euro das Stück auf deren Webside. Von "Batterero Tech". Taugen die was? Sind anscheinend deren aktueller Bestseller.

[@JayDee25895]

What??? No BMS 🤨

[@davidhopkins9021]

I think Andy knows what he's doing

[@brooklynmurrau7926]

The charger is the bms if that makes sense.

[@OffGridGarageAustralia]

No BMS for a single cell😉