3 Batteries in parallel. Lots to learn from an unfinished product 😒

[@peppeper9325]

Dear Andy, the reason why the passive cell balancing system of your batteries are unable to perform their job properly is because you are not charging your lifepo4 cells properly. The energy nedded to make a variation of 1mV at around 3.4-4.45V is a quite big energy. The same 1mV require much less energy if you balancing the cell at higher voltage, like 3.55V. At that voltage level, the passive balancing system of Seplos BMS is doing his job perfectly, you do not need any additional active equipment. Not only, there is no documented evidence that lifepo4 cell are going to degradate fastly while charging it at 3.6V instead of 3.4V. Pylontech, which has an excellent know-how in lifepo4 battery production, are setting their BMS to charge at 3.55/3.60V per cell. Think about it.

[@derfreiemensch]

What have we learned from all the videos and tests? To have a proper battery storage that runs without problems, a balancer with 1-2Ah is necessary, which automatically starts at 3.45Volt and waits below in standby with little self-consumption for its next use. This is how I run my system and have no problems . Thanks Andy I suggest that the balancers are not only supplied with extra cables, but at the ends should not be installed ring lugs, but different plug adapters, which is inserted between the connectors from the BMS and the battery cells. Would simplify the assembly and make it safer.

[@OffGridGarageAustralia]

That would be the ideal solution.

[@FutureSystem738]

Thanks Andy, as usual, very interesting 👍. (My experience: When I disconnect one of my batteries to top balance it with the JK BMS, everything equalises again very quickly once I connect them in parallel and they’re charged again, too easy!)

[@OffGridGarageAustralia]

Yes, JK-BMS is still the best to use.

[@riaanstrydom2183]

@Andy, it's time to revisit the JK BMS my friend... I feel like every single BMS after the JK had some glaring flaw...

[@OffGridGarageAustralia]

Watch this space...

[@Zorlig]

People get hung up on top balancing when diy, they shouldn't. Just get a system that will eventually balance it. These server rack batteries with communication do it for you! Just let it run a few months and check again.

[@FutureSystem738]

There’s an EXTREMELY good chance that milliamp balancing will never get the cells in balance. Because it can only balance very near the top of charge, in most cycling applications it’s just not going to happen.

[@Zorlig]

@@FutureSystem738 wow. A balancer that can't bring them into balance is one that can't keep them in balance! It's trash!

[@OffGridGarageAustralia]

The balancer on this BMS is garbage and will never balance these packs in months. I have tested it over two days and deviation got only worse.

[@liamhainsworth9620]

@@OffGridGarageAustraliaI’ve came here hoping there would be a solution to balancing battery packs. I’ve got a PACE BMS… 4 rack batteries 200ah 48v 200a BMS

[@liamhainsworth9620]

I’ve got BMS on batteries connected to victron. Dvcc is on; but solar isn’t working well: very low output: thinking maybe it’s the dvcc setting. Really struggling ☹️☹️

[@JayDee25895]

SEPLOS should be paying you for all the R&D work you do for them.

[@martdaymo]

😂😂😂😂😂

[@GapRecordingsNamibia]

Well, Andy's getting batteries out of the deal..... For me in my money that is a 20+K would be purchase...

[@JayDee25895]

@@GapRecordingsNamibia With Cash he could Buy Good Batteries.

[@OffGridGarageAustralia]

I would be glad if they listen to us and make some good batteries and more importantly, SOFTWARE!

[@Michel-7.7.7]

I stumbled over your channel today. You sound quite a lot like a german migrant, when did you flee from the mess here?

[@hilmarosterland-2602]

Hello Andy, this morning i saw a video from Andreas Schmitz, the Akkudoktor, and i remember your fight with the diodes at your older PV Panels. He finds a method show defect areas of a Panel by using a infrared cam

[@hmarc417]

And there's Bouncing Betty coming up on the inside, being tailed by Dally Ran🐴, and its Bouncing Betty for the win......YEAHHHH.....🐎🐎

[@OffGridGarageAustralia]

Yeah, hahaha, it feels like a race sometimes! 😄

[@repairman2be250]

Interesting video, thanks Andy. So, Seplos has not learned much about active balance in their BMS. Still going with a few hundred mA built in.

[@OffGridGarageAustralia]

I think it's even less than 50mA per channel these balancers are doing. If at all. No, nothing learned, not taking our feedback on board, not improving their products. We're not getting anywhere...

[@jackoneil3933]

At 19:50 Andy, I wonder if individually charging each pack (not parallel charging) with low current for several hours or days to about 57v to give the passive balancer time to top balance the cells, and once balanced if they would play better? I've noticed with the cheap passive balancing Daly BMSs, if I connect three packs in parallel they can't top balance because the the other packs hit them with more current then the BMS can dissipate so the cells never balance unless charge to about 58V and then isolate the packs and allow them to balance their cells. If I do that after every dozen charge and discharge cycles, the the Daly passive BMSs can mange to keep the packs in top balance, and I was thinking that might be adequate for parallel SEPLOS Polo users who don't want to splice in an active balancer?

[@OffGridGarageAustralia]

Yeah, I tried that with the first pack and a power supply. Not working, the balancer does not do anything and deviation actually increased because the low voltage cells didn't get any charge and voltage just decreased. I cannot charge these packs higher than 54.5V before one of the cells hits OVP. Garbage!

[@jackoneil3933]

@@OffGridGarageAustralia Oh, I see... Combine that with the case design and the glued-together cell pack and it's off my option list.

[@MrPeregrines]

Thank You for your great videos! How many hours would a JK BMS need to balance 300mv Deviation out?

[@OffGridGarageAustralia]

Hard to tell, it depends on the Ah the balancer needs to move. With these batteries, it will be balanced over night, I would assume.

[@JoseRamirez-dl7jt]

Good day Andy: After watching these two videos on paralleling batteries with busbars, I have a few questions for you. Would you recommend the use of busbars to parallel multiple DIY batteries? Let’s say Yixiang DIY boxes with 16 314A battery cells each. What would be the limit be on the number of batteries that can be connected in parallel safely using busbars? What should I be concerned about? Thank you in advance! V/r Jose

[@sharetheadventure1]

outstanding as usual Andy. After watching your videos on this setup .I know i would not be buying one. But i do love the look of it tho. I'm still building your 2.0 set up 😁.

[@OffGridGarageAustralia]

Yeah, it is not great and sucks in many aspects. They should have kept working on the software rather than bringing new products and hardware versions all the time.

[@sharetheadventure1]

I would have to agree with you on that Andy, Your 2.0 rack seems to be the best i have seen so far. lol. But i'm just going to use the JK BMS in it@@OffGridGarageAustralia

[@neelsscheepers8841]

Hi Andy. i Am so confused now. What port must i use for communication between the battery bms and the laptop, CAN or RS485 to see what the battery (Volta) bms settings is. My battery manual states that i must use a RS232 cable but that is very old type of cables that i cant find. Manuals for electronics from china don't make sense to me.

[@OffGridGarageAustralia]

CAN communication is only for your inverter. You can either use RS485 or RS232, depending on your BMS.

[@pbasista]

A battery pack with peaking cells can be balanced also by slowly increasing the charge voltage. Let the passive balancer equalize the cells at a lower voltage. Then increase it and repeat. Until e.g. 3.65 V per cell.

[@OffGridGarageAustralia]

This will not work with this BMS. The balancer is pretty much none-existent. I have adjusted the pack voltage with a power supply so none of the cells went over 3.65V and then let it sit there over night. The next morning, the voltage difference was even worse. Low SOC cells went down in voltage while the high voltage cells kept their voltage pretty much the same. I guess, the balancer is not working at all or has only a few mA of balance current.

[@Sanwizard1]

Will you be doing a review of the V3 BMS active balance module? I have 7 Masons with V1 BMS's, and wondering if it makes sense to upgrade. I kinda miss my old JK BMS's, but hoping the now available active balance module may work the same as the JK.

[@OffGridGarageAustralia]

Probably not at this stage. It is not even out yet. And why reviewing such a product which is already on the market from other manufacturers for years?! The V1 you have are actually the best BMS they have built so far (see the BMS comparison spreadsheet). It only went downhill from there.

[@junkerzn7312]

Its a good demonstration of how battery voltage gets drawn down or pushed up according to a combination of load/charge-rate and SOC. The voltage swings are the primary reason why load sharing happens in the fist place and why the load sharing tends to be a function of the relative SOCs of the batteries. Another good demonstration starting at 3:30 or so, where you were charging pack #1 and introduced pack #3 at a lower SOC. You said "all the energy should switch to pack #3". And that DID happen initially, but as pack #1's voltage settled to its new equillibrium, it began picking up some of the charging current again and again settled into a load-sharing situation that was roughly a function of the relative SOC's of the batteries. And generally this type of load sharing works quite well. Even a battery with a relatively low SOC will still contribute something when discharging. It works when charging too until the batteries actually hit 100% and potentially begin cutting off their charging entirely (though as I've said in the past, my preference is for the charge controller to handle the cut-off and for the battery BMS to just be a last line of defense, protecting the battery against individual cell over-voltages). When you began hitting the cell cut-offs... that kinda makes me believe that the batteries were not balanced out of the factory and/or the cells put into them were not matched. Which is not terrible per-say, but still a bit unexpected. It makes me wonder how much testing was actually done at the factory.

[@kuhrd]

I think the cells are reasonably matched based on testing but most of the packs being assembled and leaving China are not top balanced because they figure that will happen over the first few months that the batteries are cycled as long as they are hitting 100% and cutting off charging but continuing to balance. You even see this in the packs that are built out of the automotive grade cells where they were all matched at assembly but were never top balanced with the rest of the cells in the pack. They are just welded together and the manufacturers are relying on the BMS systems to do the balancing over time as the cells are cycled. If the software is setup correctly in the BMS no balancing at the factory should be necessary as the BMS will work on it a little at a time once the pack is put into service. I helped a friend with 2 of the EG4-LL batteries that he was having issues with and even they were not top balanced when he received them. We ended up hooking them up to a 10A power supply once they were mostly charged and stopped charging on solar and the balancer kicked in and just let them run for about 2 weeks while slowly lowering the charge current till they were within 30mv of balanced at full charge. After that we put them into service and he didn't have any more issues until he had about 3 months where the packs never saw 100% charge and he had to let the packs rebalance as they drifted a little bit over that time but they were still cycling properly but would sometimes hit a cell overvoltage condition near 100% state of charge and it would take another few cycles to full charge to balance back out. The real problem is that these batteries really need the ability to balance with at least 3-5 amps so they have a real chance to equalize before the battery reaches full charge when they come out of a long period of being on the lower end and not being charged to a high enough state to begin balancing.

[@OffGridGarageAustralia]

Yeah, great observation and analysis as always. I really like these parallel batteries and how they interact with each other. It's fascinating to watch them while charging and discharging.

[@justincooper7497]

When are we going to get a update on the diy batteries and there bms's if feels like it has been forever since we have looked at them and seeing if the bms's you swapped around helped the bottom battery on the shelf

[@OffGridGarageAustralia]

Ha! Good you're mentioning this, I have just finalised the video and it will be released in a few hours.

[@Electronzap]

You'd think the BMS would do a better job balancing them.

[@OffGridGarageAustralia]

Yes, it is really disappointing! It does not seem to work at all.

[@Dutch_off_grid_homesteading]

Heya, as you have shown a BMS with out a active min. of 2A balancer doesn't work good with LiFiPo4 battery cell's

[@R.Noordermeer]

Great test Andy!

[@OffGridGarageAustralia]

Yeah, very frustrating though. I was hoping for a great product.

[@bill2960]

Hi Andy. I think I am missing something here. Why are your Bms boards asking the solar system to reduce the current avalable to the system . I would of expected the solar system to try and maintain the dc voltage at the system voltage that you want to run at. The current would be limited by what the batteries want to take and I would have expected the Bms. To limit this current for its own battery to a max charge current Any load conection would then drawn its power from the solar system untill it can no longer keep up the dc voltage would drop and load would then come on to the batteries to make up the short fall . The important thing is to Maintan the system voltage at the correct level and not go over volt on the system. At the moment my system runs on lead acid just starting to get into. These Bms systems. And batteries regards bill

[@laurentsantaibambu7324]

Hi Andy,and thanks again for this video, But really it's disappointing!!🤔 We don't understand how they can do such things?? it does not mean anything?🙃 knowing that your tests will be watched by many people?? Finally it's their problem? But thank you again Andy, for this REAL test.😄👍

[@OffGridGarageAustralia]

I can only share what I found with these batteries, BMS and devices. Sometimes this is really frustrating, sometimes it is great.

[@laurentsantaibambu7324]

I understand perfectly Andy, and precisely it is your impartiality which is great, because you show us the reality, as always!😄👍 It's just hard to understand that a company like Seplos sends you battery knowing that your tests will be seen by a lot of people and that they don't make the effort to send you a really finished and perfect product? Doesn't that give them very good publicity? Or are they unable to do so? or are they stupid?🤔@@OffGridGarageAustralia

[@livingron9983]

Seen similar unbalance with other China batteries. They argued to me that it was industry norm to have up to 300mV deviation. Given that you are reviewing the batteries, you should not put balance boards in them. Rather, you should put them in to production as-is, and see how they balance over time... maybe months. This then would give the average person a real insight into what to expect from these batteries. Maybe they will eventually balance and maybe doing nothing is a viable choice.

[@HybridShedIraq]

I had some cells gone bad at 50% discharge deviation would be 600mv and the bad cells triggers cell low voltage disconnect.

[@OffGridGarageAustralia]

I have my deepest doubt that these packs will ever balance. The balance current is so small, it won't make a difference. Also, it is very hard to put them in production because they turn off all the time with a OVP. I can only charge them to 54V.

[@livingron9983]

@@OffGridGarageAustralia Hi Andy. I agree that they would take a LONG time to balance out, but (1) would the average user lose a lot of capacity in the meantime ... maybe 5%? (2) would they eventually balance out and how long did it take? Good to know... Victron notes in their verbage that on some lithium batteries, you need to low the charge voltage so that they stay balancing at the top end (rather than over volt) and slowly raise the voltage over time. These batteries seem to be a candidate for this treatment as they seem to be blanced only on charge? Personally, for my China batteries, I manually discharged the high voltage cells until they were close to balanced, but the average purchaser would not do that - nor install an balancer in their batteries. So while I 'feel' your temptation to just fix the problem, I think a better approach would be to' suck it and see'.

[@Lana_Warwick]

Hello Andy, just started researching, considering 5kw pv, eve 280ah 16s, not sure about inverter yet, but will be 3 phase (just myself). Curious re your smarts in this area, if you had to start off-grid again fresh, what would your shopping list be?

[@OffGridGarageAustralia]

That is a very comprehensive question. I would probably stick with the Victron gear. I really like the fact of it integrating with other systems and the ability to remotely control and manage the whole system, down to being able to change all settings from my mobile. Is 5kW solar and one 280Ah battery enough for a 3-phase system? Depends on your need and loads, I assume...

[@kristjanaiaste]

Hi Andy, coulld you maybe share a link or upload your Seplos BMS parameters that you use? I have the V2 version with parallel packs and also struggle to get them all to 100% and down equally...

[@OffGridGarageAustralia]

OK, I will do that once I have finished testing the Gobelpower battery. We will go back to Seplos and see what we can do with the V2 of these BMS. I have quite a few here which we can parallel. All the same 10E BMSes. Very tricky settings...

[@kristjanaiaste]

@@OffGridGarageAustralia That would be super! I have also NEEY balancers attached to my 5x280Ah 16S "EEL" but the SOC is driving me crazy (+ force charge setting is a mystery a bit) :)

[@zoe..d]

Your 15A axtive balancer had everything sorted in what.. half an hour?? You could take the covers off and top balance these. Longest part is disconnecting/reconnecting the balance cables. Do it 3 times and youve got your full capacity to test across the 3 banks... Take you a few hours at most...

[@OffGridGarageAustralia]

Yes, of course, I could do that. I just have the feeling that these batteries need a more permanent solution. And this should come from the manufacturer, not the user.

[@jogi_54]

In my opinion (sorry to have one), the positive cable should be connected to the upper Seplos battery and the negative cable to the lower Seplos battery. In Germany we call this Tichelman circuit in hydraulics!!! Maybee, you remember. Anyway - anyone who works with battery packs knows that the individual battery packs must be balanced to the same full voltage and then connected together. The passive balancers on the BMS's are never capable of correcting unbalanced battery sets. You told us this many videos ago - didn't you learn from your own experience?

[@volodumurkalunyak4651]

Individual packs can be connected in paralell with vastly different state of charge as long as current going from one to anouther is low enought and charge/discharge speed of those paralell packs are limited at first. Balancing individual cells within one pack - that is required either before use or with powerfull active balancer during use (for LFP - LiFePO4 during last 3-5% of charging).

[@Raphael_Hofmann]

Does not matter that much wich such low currents... Well, the Seplos 10C and 10E BMS do actually balance and are able to balance with passive balancers without problems....just takes some days...but the Seplos V3 does not balance at all...in the software, it indicates some balancing, but it is not acutally happening...

[@jogi_54]

@@volodumurkalunyak4651 did I tell anything different ???

[@stefanvanzyl9090]

the "balancers" do not function between separate packs. charging the packs up to the top point (55.2V in this case) will cause all 3 packs to be balanced on a pack-level with the first cycle, since they disconnect themselves when they're full, allowing the other packs to also reach 55.2V. With such big busbars, there is also no need to tichelman them

[@OffGridGarageAustralia]

Thanks for your comment, Juergen. Always appreciate your opinion, so nothing to be sorry about. The bus bars at the back are so fat that it does not matter where to connect pos and neg. I have done the same in my battery shelf with the copper bus bars and connecting all three batteries just from the top. No issues even when charging or discharging with 250A.

[@creamshop]

Hi Andy, can you please tell me where i can get the BMS-Studio software ?, the same one your showing in your video, i googled it cant seem to find it, Thank you.

[@AlexisZenios]

Yes please, the software looks great.

[@OffGridGarageAustralia]

It's on my website here: off-grid-garage.com/battery-management-systems-bms/ But it will only work with the V 3.0 of the Seplos BMS.

[@creamshop]

@@OffGridGarageAustralia Thanks Andy, its Realy appreciated ! 🙂

[@Der_Hannes]

Hi Andy, maybe you want to take the worst pack out of the System and just let it sit on charging with the crappy BMS Balancer to have a look how long it takes? 😀 This is a total shamy mess on seplos... I would never ever buy a product from them...crappy shit Stay balanced!

[@OffGridGarageAustralia]

The only reasonable products are their MASON DIY Kits at the moment. All this new stuff, is not ready for the market.

[@j.ccustomworkssa2090]

Good day uncle from a sunny southafrica what program do you use to monitor your bms?

[@OffGridGarageAustralia]

Hi aunty from South Africa. It depends on what BMS you have. They all come with their own specific software.

[@loucinci3922]

Agreed the packs need balanced

[@markbrettnell3503]

Well that's disappointing. You'd think that Seplos would have it together with the bms by now. Not like they're a brand new company now.

[@OffGridGarageAustralia]

The V1 of their BMS was the best (FW 2.8) and actually worked quite well. They could have kept this and just updated with new software. It was great and even got 4 frogs in my comparison spreadsheet. FW2.9 for this BMS was a step backwards already, V2 of the BMS was bad and never worked well. V3 was my big hope... I don't understand why they develop new hardware all the time instead of just working on the software and implement the features and functions from our feedback🤷‍♂️

[@mario-q6k9w]

Even if the battery is balanced, doesn't the CVL of 55.2V ensure that the battery stays at that level all day?

[@stefanvanzyl9090]

no, if the CCL is 0A, then the mppt has no tools at its disposal to push the voltage up with.

[@OffGridGarageAustralia]

It will stop charging at this point but will turn on again once SOC goes below 100%. So 99.9% opens the MPPTs again and it will get recharged.

[@hero234ist]

Thanks for the video!

[@camielkotte]

Oh ! Sweet amps , they are like brand new toys. Nice vid! Curious, will it balance after time? Say 3 months of use with regular full charge? What is the recommended balance start voltage according to Seplos? They do balance during charging? (Before 3.45 volts) I know my 0.6amp JK did a fine job starting balance at 3.40 and absorb at 3.45 for 20 minutes or 2hr. No difference. Now testing with 2a balance at 3.45/2hrs. Let's see what is faster. I may have to induce a voltage diff manually to test fairly.

[@OffGridGarageAustralia]

I doubt that they will ever balance. I had it siting with a power supply connected and the voltage delta got worse after 24h. The 0.6A JK-BMS is brilliant and would work a lot better than the V3 of the Seplos BMS.

[@typxxilps]

it slowly becomes an australian SEPLOS LABORATORY with 5 seplos batteries in 2 towers. The Neey Laboratory has finished with the Neey 4th generation which really works fine.

[@Zorlig]

It's ok... Could still use a fifth gen on the neey. Still doesn't operate as desired or give you full control of the voltage

[@OffGridGarageAustralia]

The V4 of the NEEY Active Balancer is great and works perfectly.

[@Zorlig]

@@OffGridGarageAustralia it works really well, but there are some issues. For example in your video your initial settings failed. I've confirmed that on mine too - if they are too high you get that voltage too low message. You can trick it some, but it only works for one cycle. It also starts balancing based on the average cell voltage when it should use the highest cell.

[@guywhoknows]

That's actually bad. I've got 32mv and 46mv difference on two parallel 7s old laptop banks. And only one has a BMS... Our commercial pack cells come with 0.001mv difference in packs. You need to discharge and recharge with an active balancer, usually coming up over 80% gives the balance time due to the resistance change on the cells. Or You could manually balance the cells, that's like paint drying..

[@OffGridGarageAustralia]

Yeah, I really don't like fixing their sh!t all the time. The balancer does not seem to work at all.

[@guywhoknows]

@@OffGridGarageAustralia maybe it does work, it's passive , and so tiny that it would take a month to balance? I've a small active balancer and it takes 10+ hours to balance a small pack.

[@HybridShedIraq]

After replacing 5 cells in my 280AH pack now i have 2 group of cells at top balance, group of 8 cells that stay at 3.45 and a group of 8 stays at 3.385 now 10 days lets see what JK can do about them. good luck balancing those new Seplos cells. I charge them max to 54.6v though.

[@OffGridGarageAustralia]

I hope you're not talking about LiFePO4 cells here. these voltages are far too high and dangerous for LFP cells!

[@HybridShedIraq]

@OffGridGarageAustralia my mistake, sorry, I meant 3.45. And yes they are LFP.

[@komplikatorful]

About those voltages: you really have to look at them *before* you switch on the breaker to judge the charge state of the battery, not after. Because when you turn it on, the other batteries will quickly "level out" as they will be pushing current to the discharged one - and you only get few millivolts of a difference. You can see it @ 3:38 - the third pack has 51.63V while the others have almost 53V. When you switch on the breaker, the voltage will meet in the middle (causing big current to flow) around 52.5V. 🙂

[@onthelake9554]

SOC not determined by V .

[@komplikatorful]

@@onthelake9554 Yes and no - the discharge curve is quite specific and while you cannot tell the difference between (lets say) 75 and 85% you certainly can tell the difference between 10% and 90% :)

[@onthelake9554]

@@komplikatorful My reply wasn't a question. Andy had intentionally made the SOC unbalanced.

[@komplikatorful]

@@onthelake9554 I don't think I said it was a question. It was definitely wrong - atleast partially though. And I also don't think that whether he's done it intentionally or not is completely irrelevant to what I was talking about. 🤷

[@onthelake9554]

@@komplikatorful Thanks for reminding me not to engage when I feel the need .

[@wayne8113]

Thanks Andy

[@OffGridGarageAustralia]

Thanks, Wayne!

[@nielsdelrue7242]

End over a couple of months the lmfp cells are on the market.

[@nekoroms]

I was wanting to see the individual battery cells as there seemed for the 2 seconds we could see that window in the software to be huge differences :)

[@OffGridGarageAustralia]

All three packs have over 250mV voltage difference and I cannot even charge the packs to 55V without one cell hitting 3.65V. And the balancers don't seem to work at all.

[@jackoneil3933]

Thanks for the outstanding demonstration instruction. I would love to see a mixed chemistry parallel test with Lead-Acid and LFP, with larger capacities and loads than I've done at small scale. Mainly for people like a friend with an off-grid home in Thailand who's been running a deep-cycle Lead-acid pack and needs to add capacity and is considering doubling his battery capacity with a new LFP pack, and had concerns about connecting it in parallel with his lead-acid pack. He said local solar dealers informed him that will ruin his lead acid pack and cause heating and all sorts of charging and discharging problems. I believe this is bunk as the LFP Packs should handle most of the high load peaks with the Lead acid batteries following in trail. As many may be wanting to add an LFP pack to a Lead Acid pack perhaps such as test would be useful information. I have observed when paralleling similar sized 48V Li-ion packs with LFP packs (600 watt-hour each), that under prolonged high load (about 1000w) from 100% SOC to about 70% SOC, the Li-ion pack will end up as a lower state of charge and after removing the load, and LFP pack will charge the Li-ion pack at about 500watts or at the charge limit of the LI-Ion pack. My though is that this would be reversed if connecting a Lead acid pack with a LFP pack, and the LFP pack would handle most of the discharging and charging load.

[@bascomnextion5639]

I am running lead acid an Lifepo4 in parallel its working just fine the Lifepo4 handles 99% of the load if you discharge down to 20% for the Lifepo4 a small amount will come from the lead acid. I have set the back to grid/generator at 49 volts which on my old batteries means they do not do much , I tried at 48 volts for testing and the lead acid started to provide 15% of the load. So basically the lead acid remains mostly on float. Note I have set the charge voltages for the Lifepo4 so defeating the lead acid charge profile. I have a daly bms on 16 x 280Ah Lifepo4 one system on another system I have a 310Ah green bank battery bms is not accessible but the indicator on the front matches that of the one on the daly bms on the other system. If you go to the Australian Electric Vehicle Association forum renewable energy and storage (non - ev) I have started a topic for this now.

[@stefanvanzyl9090]

Mixing battery chemistries like this is not feasible. Due to the flat discharge curve of LFP batteries, you will empty your LFP before the lead-acid starts to do something. Due to the flat charging curve, by the time you reach the absorb voltage for your lead acid batteries (56.8V to 58.4V, AGM vs FLA), your LFP battery will be overcharged already, and you have to keep this absorb voltage for an extended duration for the lead acid to charge. this will cause your Lithium BMS to disconnect every time. If you have a poor solar day/week (lithium only charged to 80%), then your lead acid will never charge, and this will damage them.

[@jackoneil3933]

​@@bascomnextion5639 thanks very much for the information. That's similar what I observed with some limited testing I did with 2000 watt-hour 12v deep-cycle lead acid and 600 watt-hour 12V LFP pack. but once I got below 3.20 volts per cell or 12.8V system voltage the Lead Acid started providing 50 to 80% of the load as the voltage dropped to the cut-off voltage of the LFP pack.

[@bascomnextion5639]

Flooded lead acid need 62 volts for a proper charge so almost all chargers do not charge them properly sealed lead acid should be kept below 57 volts but benefit from pulse charging to 62 volts . Regular maintenance is a must for lead acid so part of this would be to charge the battery at least monthly to these voltages , I use a 5 amp 48v pulse charger to do this. I have also a nickel iron bank which needs 64 volts to solve this some of my mppt chargers have an load output that can be set to come on/off at a set battery voltage so with a large relay/contactor I disconnect the NiFe battery from the system and the mppt charger with its solar takes it to 64 volts a similar voltage controlled relay could do the same with lead acid banks switching to a charger.

[@CantFindInYoutube]

In winter I mix Lead acid with LFP and they work very well, the BMS OVP and UVP will fire on every charge/discharge to protect the LFP but the Lead acid will extend the capacity the capacity of your pack. I mix them to have capacity to reach the period when the grid rate is lower. One thing that you must consider is that acid must be in good shape or they will drain energy solar energy that could be used to charge the LFP. In summer I don't use lead but charge them every month and notice that LFP capacity is lower in the morning before solar kick in and I produce twice of what I use, so this means that at night lead is draining power from LFP.

[@tenoirab]

the power is soley comming from the battery and not form solar, because you don't have your battery shunt (the discharge test shunt) hooked up and set up as DC-Load Meter in front of the "peter-inverter" so the victron system asumes there is only batteries behind the mppt's and the BMS requests 0 Amps charging, that's what the mppt is doing. you can see @20:52 the blue victron symbol in the middle (usualy a MultiPlus) is still in "off" state. Try to test this with the shunt hooked up to the s.p.a.t.-centre, would be interessting to see if this works!

[@OffGridGarageAustralia]

That's not the case as the V1 and V2 of the Seplos BMS work exactly with the same hardware and 'report' the DC load correctly to the Victron system. I don't need a Victron shunt if I have a smart BMS installed. All BMS have a shunt which measure exactly the same current as the Victron shunt would do. The BMS just does not report it correctly.

[@trevortrevortsr2]

I've seen this dance between the charger and the BMS - I didn't like it - Micro cycling on knee has got to shorten the lifespan and cause the cells to "Pant" - My solution was to fit a 5amp active cell balancer on an additional set of leads and drop the charger vo;tage to 3.55v a cell - now the charger controls the charging and the BMS protects the battery if something fails - no more 3.65 over charge alarms

[@OffGridGarageAustralia]

Exactly, other BMS can handle this much battery. Seplos V1, the Tiangbangda and PACE BMS, the Gobelpower BMS. All working well without micro cycling the battery and keeping the MPPTs open to deliver power. This V3 BMS here is terrible and I hope they can fix the software without developing yet another BMS instead.

[@jurajnikolov4219]

Andy, I admire you for having the nervs for this Seplos.... :D :D :D

[@OffGridGarageAustralia]

I need to know myself, so happy to share this her eon the channel...

[@jurajnikolov4219]

@@OffGridGarageAustralia OK, but I think you already understood that Seplos is a terrible waste :D :D :D ... there are so many different and functional solutions ... you even built one of them ...

[@OffGridGarageAustralia]

@@jurajnikolov4219 For years (not quite...), people wanted me to test the Seplos BMS because of the great communication to inverters. Well, even the communication works well with these BMS, the software and design needs a lot of work. I believe Seplos is not big enough to have a say in how the software should be or even can request certain features in a new software update. If all these BMS have the ability to be updated via software, why is nobody listening to the community and make all these changes via a software update. It is sooo easy. Users can then decide which version they want to run with certain functionality.

[@jurajnikolov4219]

@@OffGridGarageAustralia I've never seen it go without problems :D communication, balancing... :D And you already have a built-in solution that is functional and does what it is supposed to do :D Ok, you don't see cell states, monitoring... sacrifice one Rasspberrrpiiiii for each BMS :) for that venusOS, then as a solo installation in VRM... I assume that it will be possible to unify via rednote, or you can see it as a solo installation under VRM, what I'm writing :) How many times do you do the settings? When do you sett it and then?

[@edc1569]

The packs could be perfectly bottom balanced?

[@OffGridGarageAustralia]

Nobody is bottom balancing any more. All BMS and balancers are doing top balancing. It is far more efficient and what everyone is doing for years now. Bottom balancing is from a time where we didn't have reliable BMS and balancers. Hey, you may be right here as these batteries don't have any of that 😂😂😂

[@wholepowermarket]

Great video👍

[@OffGridGarageAustralia]

Thanks 👍

[@airgead5391]

You need a neeeeeeeey!!! (well, three of them)

[@OffGridGarageAustralia]

Yes, or a different BMS... 😉

[@Juergen_Miessmer]

They look very pretty - so, who cares for technical shortcommings ;-)

[@FutureSystem738]

LOL :-) 😂

[@jackcoats4146]

Wouldl bottom balancing them help? Just curious...

[@FutureSystem738]

IHMO: No.

[@OffGridGarageAustralia]

No, bottom balancing is a thing from the past where we didn't have any good BMS or even balancers. Nobody is really using bottom balancing any more. All the devices and tech does top balancing. It's the far better method.

[@markwright196]

I think you mean the chemistry state figures it out.... figuring it out implies a process or communication .... You are not implyinng the BMS does this right?

[@GapRecordingsNamibia]

For a company that has been in the battery game for so long, one would think that they would listen to you, and, to have issues like this, at this stage of the game for them, is somewhat disappointing. As always good feedback, let us hope they will get caught up, the one thing that does bother me though, how long have you been advocating for active balancers, now, they have one but it is an "extra" purchase and can't be programed. That is very disappointing.

[@OffGridGarageAustralia]

We, the community provided them with so much feedback over the last year or so, but it seems they stick to their guns and chose to ignore all of that. It is a real shame as the batteries and BMS have so much potential. I provide them with a lot of feedback about their products but it does not seem to improve.

[@GapRecordingsNamibia]

@@OffGridGarageAustralia Yip, it is a pity Andy..... Especially locking a product down so hard that it is basically useless to anyone else.....

[@brucebugbee6604]

Disappointing. The form factor of the Seplos batteries look great, but the fact that they are not top balanced (not even close) shows a lack of quality control in my opinion. I'd just take out the communication cables and let the whole pack charge to a set voltage and see what happens.

[@OffGridGarageAustralia]

Yeah, I was kind of disappointed as well. If there is no top balancing, that's fine but then they need to supply a working balancer and not this joke of BMS 3.0

[@sommeone4582]

Why didnt you charge them to same level before putting in parallel??

[@stefanvanzyl9090]

to show you that it's inconsequential with the BMSes we have available today. it is not important anymore

[@martdaymo]

Thease issues wouldn't matter with a AC coupled arrangement.

[@deh_developer2725]

How much Watts Hours can you gain with a full balanced battery?

[@stefanvanzyl9090]

1-50%, depending on how unbalanced it is.

[@paulcurtis5496]

I don’t know if it is my OCD or SOC anxiety but if the sun is out my battery is charged by 10am. Being 100% off-grid probably contributes to this…

[@perpelle]

What SOC do you have before the sun rises?

[@paulcurtis5496]

@@perpelle when it’s 110°f at sunset, 28ish%, during Winter it’s normally between 40-50%.

[@OffGridGarageAustralia]

Well, it depends on the size of you battery. I could be fully charged at 10am with a small battery.

[@paulcurtis5496]

@@OffGridGarageAustralia atm I have 1 Big Battery Rhino (14kWatt/hr) on the way to 8. Before I over-paneled The earliest I hit 100% was around 1:30p-2pm. Now I hit 100% around 9:30a - 10a. I want from 2.7kWatt/hr to 6.545kWatt/hr with my panels.

[@paulcurtis5496]

Actually, I over paneled because I was up in Flagstaff during a winter storm and after 2 days the Rhino was tapped out. It was -12°f over those three days. I had to actually drive down to Verde Valley to get sunshine, charge up and then headed back to Flagstaff. It was far cheaper to add solar than the second battery.

[@ThanosSustainable]

No big deal, imo. The cells will eventually top balance, after 100 or so cycles.

[@OffGridGarageAustralia]

I really doubt they will ever balance. I've got them in a production installation now for a week and deviation actually got worse. The balancer is either not working at all or is so tiny, that it does not matter.

[@ThanosSustainable]

@@OffGridGarageAustralia if it got worse, maybe you’ve got a self-discharging cell.

[@OffGridGarageAustralia]

@@ThanosSustainable In all three batteries? I think the deviation is far too big for the passive balancer to deal with. After 2 weeks, I will just manually top balance the packs and try again. Maybe this gives the balancer a chance. If it still fails...🤷‍♂

[@DanBurgaud]

I have a question for you regarding SOC% counter. Assuming you charge - discharge a 16S battery pack within 51V and 54V only for at least 3 months, do you think the SOC% will be accurate?

[@stefanvanzyl9090]

it will not be accurate. BMSes with cheap coulomb counters struggle a lot to measure low currents (less than 0.5A is usually just zeroed), and it can either drift upward or downward depending on your actual charging and discharging rates. You need to reach the calibration point at least weekly to ensure your BMS knows the state of charge, otherwise that number means nothing and will cause you to run your batteries down further than you planned. Calibration point for many BMSes is unfortunately at cell overvoltage (3.65V), and would thus need up to 58V for a 16s pack to calibrate. also keep in mind, at a slow discharge rate, 51V total for an unbalanced pack can be as low as 10% SoC

[@OffGridGarageAustralia]

Each shunt needs some sort of calibration from time to time. The current measurement (coulomb count) is not accurate and the SOC will drift over time.

[@ClausMallorca]

You can't avoid the active balancer!😢 I guess

[@Zorlig]

You can, just ignore it and over enough time those BMS will do it for you over a few months.

[@OffGridGarageAustralia]

Active balancer is a must for these batteries. Or at least a working balancer would help as well...

[@igorkvachun3572]

Yes video.👍⚡🔋💡

[@unionse7en]

SPAT CAN communications lol

[@Tobarja]

BMS Studio... whose app is this?

[@typxxilps]

new seplos bms software - but I think I have seen it also on another battery but can not remember where I had seen the bright green color

[@OffGridGarageAustralia]

It's on my website to download. I doubt it will work with any other BMS than the V3 of the Seplos BMS. off-grid-garage.com/battery-management-systems-bms/

[@paulbarrette2557]

Love your videos but I am getting a bit tired of SEPLOS product reviews to be honest. Is there really that many people that use SEPLOS products?

[@OffGridGarageAustralia]

Thanks for your feedback, Paul. I'm sharing what I'm doing in my garage. Some people may not be that interested in BMS testing, battery built or solar panel installation, so I would suggest to just skipping these videos. But to answer your question, I would say, we're pretty much done with SEPLOS now. I cannot see any benefit of their BMS and software and there is pretty much no progress from their previous versions.

[@paulbarrette2557]

@@OffGridGarageAustralia Yeah, sorry if my comment seemed harsh. You can't please everyone. And yes I do skip them. I like your videos a lot and look forward to them ... For ME, when I see a Seplos video... I am disappointed and need to put the popcorn back in the pantry and wait for the next one. haha

[@jamesstubbins3510]

Try conecting positive to battery No. 1 and negative to battery No.3, that way the load will be balanced from all batteries

[@OffGridGarageAustralia]

Does not make a difference when using beefy bus bars.

[@dingsvomdach6764]

With your new neeeyyy high Power aktive Balancer you could Balance them ome by one in short time. This type of cells seems to be Garbage 😅 or only the bms ?

[@OffGridGarageAustralia]

I think the BMS sucks donkey balls. The software is not great and also the balancer is so weak, it does not do anything with these cells. A huge step backwards in my eyes from what they had before.

[@ch-solar2293]

Neeeeey is the Solution :-)

[@OffGridGarageAustralia]

Yes and no. The manufacturer need to fix this by including a balancing function WHICH ACTUALLY WORKS.

[@VASYL.MELNYK]

After one year using two batteries i build one battery 16s2p - i think is better then 2x16s1p. I have seplos bms 200a and voltronics axpert max 7200 with 150a continues discharge.

[@typxxilps]

there is only one downside cause with 2 batteries you can put the 16 strongest with the highest capacity into one battery and gain a bit of capacity but have to pay for 2 bms and also for the energy they need to run.

[@VASYL.MELNYK]

@@typxxilps I counted a few examples in excel - it all does not have much effect. 10-20 amps by battery it's 500-1000watts -

[@OffGridGarageAustralia]

I'm not a fan of parallel cells and like to have a separate BMS to monitor all cells individually. This is for monitor and safety reasons.

[@MichaelHigginsJR]

Lame, my eg4 batteries have similar issues with my 3000lvm

[@OffGridGarageAustralia]

Really??? I thought this is a Seplos problem only...

[@cskeise]

💙👊😎

[@paulcurtis5496]

Like# 15

[@cyberplebs6577]

🐸🐸🐸

[@InspectorGadget2014]

Sadly I had a feeling you would uncover more & more quirks. Of course it stands and falls with the manufacturer understanding, accepting and resolving the issues you have found. Your feedback should be considered as gold (sunshine), with all those testing you already have done for the channel. When the manufacturer ignores you or refuses to fix issues (or responds) , than I guess they will not get any Andy's Frogs. I agree, (e.g) the NEEEEEEY active balancers can help resolve the huge imbalances, maybe than the SEPLOS will also perform better? As right now, it really does not look too positive for the SEPLOS on multiple levels, it sucks donkeyb.lls in my view... I do hope you had not to pay for the SEPLOS, as I would be very disappointed for that amount of money (investment) and such poor results. But thanks for sharing, it strengthens my conviction & believes that the Gobelpower is the far better BMS for such scenarios. And SEPLOS should thus be avoided until they fix their sh.t.

[@OffGridGarageAustralia]

Yes, 100% agree with your comment. The donkey balls are strong in these products unfortunately. They should have kept the V1 of the BMS and worked on the software. It would have been great by now...

[@jasontaverner2634]

the spent too much time and effort designing nice looking cases and not the essential BMS software/firmware, IMO

[@OffGridGarageAustralia]

Yes, exactly, they put a lot of effort in their products but don't get them tested properly. I offered them 100 times to send stuff over for me to test and give them feedback before they release it to the market. I think it's a cultural thing and they don't take critics from the outside well.

[@Once_in_a_Lifetime]

I don’t see how the cost of this equipment is worth replacing the grid! This is simply boggles the mind. This is all wasted if any thing happens to you. No one will bother trying to figure how this all works. You need to sell the place and include your tutelage on how to make this all run. Otherwise all the expenditure on this equipment will be wasted.

[@OffGridGarageAustralia]

Any electrician can maintain it (if there is anything to maintain).

[@jws3925]

Not top balanced from the manufacturer! Yikes.

[@OffGridGarageAustralia]

Yes, not great!

[@billy-go9kx]

Send that crap back to the company. Let them try again to make something that works.

[@OffGridGarageAustralia]

If they could update the software on the BMS, it would actually work.

[@mortenwinslw2785]

60mV, not 6mV😉😉😉

[@paulcurtis5496]

Marco needs to show up and straighten out the imbalanced state. Difficult to believe a production product is so immature…

[@OffGridGarageAustralia]

Yeah, it's not great and I cannot even use these batteries as they are because they have OVP all the time.

[@anthonyrstrawbridge]

🍺🥒Prost

[@OffGridGarageAustralia]

Joh, cheers!

[@alsemi-back-up579]

Why Do You Even Bother With These JUNK Seplos Batteries!!!!!!!!! Beats Me!!!!!!! Oh Well Your Australian Dollar Waisted!!

[@OffGridGarageAustralia]

I'm interested in the tech, so sharing this here on my channel...

[@alsemi-back-up579]

thanks for the quick reply Very frustrating Seplos Batteries Not Going To Purchase Until YOU Solve All Problems Thanks for the upload I am hooked on your channel NOW Sub Thanks for the Raspi Info Channel Say On a Matchbook Running Victron Venus Os on a Raspi4 Also Easy to program on a Mac Enjoy your Day Cheers from Canada @@OffGridGarageAustralia

[@erwa8729]

I guess what your plan is: This is a job for the neey balancer.

[@OffGridGarageAustralia]

Or the 5A balancers with a voltage trigger module...

[@janbws]

Først

[@JayDee25895]

can't see it for the trees 🤣🤣🤣🤣🤣🤣🤣

[@cliffwillson3643]

Sekand

[@plokijij7856]

I have such a dislike of pouch/polymer cell batteries they gives me anxiety with memories of my sons RC car racing days! They gas so much which cause pack swelling, once one pouch goes bad it effects the lot. All the thermal runaway videos you see with scooters, hoverboard ect are pouch batteries! Wouldn’t matter what “parameters” was set to I wouldn’t be able to sleep at night with these cycling in my garage! 🔥🧯 I don’t even charge my mobile phone over night 😂

[@stefanvanzyl9090]

these are LFP batteries, they are completely different to your experience of Li-ion cells. It's like saying you will never eat oranges again because you bit into the pip of an apple.

[@plokijij7856]

@@stefanvanzyl9090 yeah there fine! There probably Ganfeng LiFePO4 3.65v 152Wh pouch cells like the ones Prowse put a drill through 👍

[@ralphg3315]

If you would follow the instructions of the battery and would have charged them and discharged them in the first place. You wanted to have in the problem. This is why they give you Instructions in the with the battery.

[@patricklyons7683]

It's about testing for problems & issues. By deviation you discover problems.

[@volodumurkalunyak4651]

Following an instructions will fix only one of the problems: BMS doesnt reported correcly state of charge (until finishing the first cycle). All of balancing issues will be still there

[@Raphael_Hofmann]

Andy Knows what he is doing...the problem is the balancing and the settings...

[@Raphael_Hofmann]

Yes, he would not buy them himself...and his verdict is clear in my eyes: Don't buy them.@@cdonuts7335

[@OffGridGarageAustralia]

The calibration of the BMS has nothing to do with the poor balancing function. Total garbage.