October 19, 20214 yr Agree with you wholeheartedly @Sarel, BUT I have two Pylontech 2000 batteries hooked up to a 5 kW Sunsynk, I do use a kettle/microwave at night plus the tv,LED lights and fridge/ freezer and don’t have an issue. Unfortunately not everyone can afford to spend major bucks on batteries and have to make do with with what they have
October 19, 20214 yr 1 hour ago, Nexuss said: Then you did not plan/manage the system correctly,its really not that hard to avoid that scenario through minor planning. There should also ideally not be such a large draw on the essential side of the 5kw inverter ,only absolute essentials ,Keith makes this pretty clear in his training videos. How much does Keith say, you should draw sustained from a 5kW SunSynk? Link to the exact video?
October 19, 20214 yr 51 minutes ago, Tariq said: Hasn’t happened yet, I am not knocking Hubble, in fact, if Hubble had been around when I was buying my batteries, I would have gone for the Hubble, as they are located on my doorstep ( local manufacturer ) Agree with @Nexuss, don’t believe 1C is such a big deal Did you check out the link i posted ? If hubble made a LiFePO4 battery i would probably recommend it,but for home storage there is really no reason to use the NMC chemistry.
October 19, 20214 yr @Tariq, these are just facts. Every person does what they can within their means. It's not meant to say anybody is doing stuff wrong, it's just the facts. Your system, it's my guess, are within design specs, or at least close to that, by the looks of what you mentioned, I could be wrong. It does not matter if I am right or wrong, it's your system after all. My observations is only because of best practise from power design considerations, warrantees etc.
October 19, 20214 yr 1 minute ago, PowerUser said: How much does Keith say, you should draw sustained from a 5kW SunSynk? Link to the exact video? He does not say an exact amount , he only said you should keep it to the absolute essentials and if you dont you wont be having a good time/using the inverter as intended. Cant say in what video exactly as i have watched almost all of them they are all kind of blended together in my mind now.
October 19, 20214 yr 4 minutes ago, Nexuss said: Did you check out the link i posted ? If hubble made a LiFePO4 battery i would probably recommend it,but for home storage there is really no reason to use the NMC chemistry. There is a very good reason! It's price! Find me a 5.5kWh LiFePo4 battery on the market, which can do 1C. E.g. match the inverter capabilities.
October 19, 20214 yr 1 hour ago, Nexuss said: Heres a nice bit of reading that you might find interesting. https://www.onecharge.biz/blog/lfp-lithium-batteries-live-longer-than-nmc/ Exactly who are Onecharge, who owns them, and perhaps most important of all, what products do they sell? I was actually looking forward to @ASH_JHB response though, because he expressed concern and I wanted to understand his reasons. Edited October 19, 20214 yr by YellowTapemeasure
October 19, 20214 yr 6 minutes ago, Nexuss said: He does not say an exact amount , he only said you should keep it to the absolute essentials and if you dont you wont be having a good time/using the inverter as intended. Cant say in what video exactly as i have watched almost all of them they are all kind of blended together in my mind now. The inverter is rated at 5000W nominal power. That means, you should be able to draw 5kW sustained and you should have a battery to match and provide the necessary AMPS at discharge, in case a cloud comes over or Eskom fails while drawing that power. The Pylontech 4.8kWh LiFePO4 battery will fail at that exact point of time. Edited October 19, 20214 yr by PowerUser
October 19, 20214 yr 2 minutes ago, PowerUser said: There is a very good reason! It's price! Find me a 5.5kWh LiFePo4 battery on the market, which can do 1C. E.g. match the inverter capabilities. If you are willing to sacrifice lifespan for 1c capabilities i dont know what to say except get more LFP batteries/larger batteries. To Get to 6000 cycles on the AM2 you can only do a DOD of 50%...
October 19, 20214 yr 3 minutes ago, YellowTapemeasure said: Exactly who are Onecharge, who owns them, and perhaps most important of all, what products do they sell? Why does that matter ? there is a link to the study in the article? https://iopscience.iop.org/article/10.1149/1945-7111/abae37
October 19, 20214 yr 1 minute ago, Nexuss said: If you are willing to sacrifice lifespan for 1c capabilities i dont know what to say except get more LFP batteries/larger batteries. To Get to 6000 cycles on the AM2 you can only do a DOD of 50%... Do you think, you will get to 6000 on your LiFePO4? How much will be the lifespan is yet to see. But in order to match the AM-2, you will need double capacity LiFePO4 in order to match the draw current.
October 19, 20214 yr 4 minutes ago, Nexuss said: Why does that matter ? there is a link to the study in the article? https://iopscience.iop.org/article/10.1149/1945-7111/abae37 From your link: LFP cells had the highest cycle lifetime across all conditions, but this performance gap was reduced when cells were compared according to the discharge energy throughput.
October 19, 20214 yr 10 minutes ago, Nexuss said: Why does that matter ? It may not to you, but it does to me, there's far too much "bad science" out there. I am very circumspect regarding sources of knowledge. t do read journals from reputable sources and authors, that are exposed to peer review and that aren't funded or sponsored by any businesses that stand to profit from their findings. I am not casting aspersions on the article or the "study", but I thought that since you recommended it as an authoritative source, that you might know the answers to my questions. Edited October 19, 20214 yr by YellowTapemeasure
October 19, 20214 yr 27 minutes ago, PowerUser said: Do you think, you will get to 6000 on your LiFePO4? How much will be the lifespan is yet to see. But in order to match the AM-2, you will need double capacity LiFePO4 in order to match the draw current. Yes i do think so , if you look at the studies 6000 cycles is not that hard to do for LFP ,thats why they can give you a warranty for 6000 cycles @ 95% DOD easily. You dont need double the capacity in NMC cells to match LFP , for example you need 5 3,5kw pylons @ 17.5kwh capacity to max out a sunsynk 8kw or 2 AM2's @11kwh capacity, so far from double. Edited October 19, 20214 yr by Nexuss
October 19, 20214 yr 1 minute ago, Nexuss said: Yes i do think so , if you look at the studies 6000 cycles is not that hard to do for LFP ,thats why they can give you a warranty for 6000 cycles @ 95% DOD easily. You dont need double the capacity in NMC cells to match LFP , for example you need 5 3,5kw pylons @ 17.5kwh capacity to max out a sunsynk 8kw or 3 AM2's @16.5kwh capacity, so far from double. I'm not referring to capacity. If you have the money - spend as much as you can on capacity. However.....you will need to parallel 2 x LFP in order to match the draw current from the AM-2.
October 19, 20214 yr 1 minute ago, PowerUser said: I'm not referring to capacity. If you have the money - spend as much as you can on capacity. However.....you will need to parallel 2 x LFP in order to match the draw current from the AM-2. You literally said capacity haha ,and yes you wil be paralleling more batteries most likely with LFP ,thats not a problem though.
October 19, 20214 yr 2 hours ago, Nexuss said: Then you did not plan/manage the system correctly,its really not that hard to avoid that scenario through minor planning. There should also ideally not be such a large draw on the essential side of the 5kw inverter ,only absolute essentials ,Keith makes this pretty clear in his training videos. Well 2 x 2.4kwh 0.5C batteries on a 5kw inverter isn’t planned correctly. That’s why I asked the question. Drawing 4.8kw on the essential isn’t a large draw on a 5kw inverter. I have seen it often where someone has a kettle and microwave on at the same time. That’s not bad management. And no installer I have seen puts those items on the non essential side. So C rating is important.
October 19, 20214 yr Two 2.4 kWh batteries was not a design choice, it was a matter of what I could afford at the time and essentially not much else was available at the time I have come to the conclusion ( for me ) that 0.5C is not an issue, so to each his own
October 19, 20214 yr 1 hour ago, Tariq said: Two 2.4 kWh batteries was not a design choice, it was a matter of what I could afford at the time and essentially not much else was available at the time I have come to the conclusion ( for me ) that 0.5C is not an issue, so to each his own You said that you are willing to learn so I asked you what would happen in your setup if you are drawing 4.8kw on your essential side and the grid fails at that instant. Instead of merely giving me a straight answer, you decided to say that it hasn’t happened yet. @Nexuss decided to answer my question that I asked you by saying that its an unplanned system. So maybe he can advise on a better planned system. On the one hand the argument is finance yet the other hand says, just buy more 0.5c batteries. As you said, each to their own so I shall leave it at that.
October 20, 20214 yr 8 hours ago, Leshen said: You said that you are willing to learn so I asked you what would happen in your setup if you are drawing 4.8kw on your essential side and the grid fails at that instant. Instead of merely giving me a straight answer, you decided to say that it hasn’t happened yet. @Nexuss decided to answer my question that I asked you by saying that its an unplanned system. So maybe he can advise on a better planned system. On the one hand the argument is finance yet the other hand says, just buy more 0.5c batteries. As you said, each to their own so I shall leave it at that. Well if it hasnt happend yet how is he/we supposed to know what would happen ? Why dont you just tell us as you clearly know the answer? I would suspect the inverter would either trip and or give an alarm . A better planned system would have battery power to support the 4,8kw of appliances that you put on essentials. If you want that many appliances on essentials get more batteries,or move loads to the non essential. Better planning would be to never have more loads on the essential side than what your battery can support , this is very easy to do. This is definitely not a reason to go for NMC cells though . Ask yourself , why does all the top batteries for solar storage use LFP ? Blue Nova,BSL,Freedom Won,Pylontech ,MD solar ect, all use LFP cells.
October 20, 20214 yr Hi All Just my opinion i bought a hubble AM2 not because of the brand just base on the 1C rating as I sometimes draw around 96amps about 5000w. I have the Sunsynk 8Kw so it delivers what I require.
October 20, 20214 yr 1 hour ago, Nexuss said: Well if it hasnt happend yet how is he/we supposed to know what would happen ? Why dont you just tell us as you clearly know the answer? I would suspect the inverter would either trip and or give an alarm . A better planned system would have battery power to support the 4,8kw of appliances that you put on essentials. If you want that many appliances on essentials get more batteries,or move loads to the non essential. Better planning would be to never have more loads on the essential side than what your battery can support , this is very easy to do. This is definitely not a reason to go for NMC cells though . Ask yourself , why does all the top batteries for solar storage use LFP ? Blue Nova,BSL,Freedom Won,Pylontech ,MD solar ect, all use LFP cells. Maybe read what I post or at least try to understand the words. Im referring to C rating, not a brand or chemistry. Try educating yourself and note that Freedom Won is an LFP battery with a 1C rating. Pylontech isnt.
October 20, 20214 yr 2 hours ago, Nexuss said: A better planned system would have battery power to support the 4,8kw of appliances that you put on essentials. If you want that many appliances on essentials get more batteries,or move loads to the non essential. And the best planning would be to have a battery which matches the inverter required current and not only kW. But you refuse to understand that because, if you can type few words in a Google search bar, you get fixated by some title on few articles and think, you have become an expert on battery chemistry and longevity. On car capable of doing 280km/h, you will put not only the correct size tires but also correct speed rating tires (at least rated for 280km/h). You won't put tires rated only at 120km/h because that's the maximum allowed speed on the roads. Edited October 20, 20214 yr by PowerUser
October 20, 20214 yr Hi guys, I will be the first one to apologize, I did not want to create any ugliness on this forum, I am truly sorry, let us all be friends.
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