October 20, 20232 yr Andy continues to amaze me with his tests, saving us a ton of time with understanding how lithium iron phosphate batteries work. this is one of the best explainer videos I have seen in a long time.
October 20, 20232 yr 8 minutes ago, WannabeSolarSparky said: Andy continues to amaze me with his tests, saving us a ton of time with understanding how lithium iron phosphate batteries work. this is one of the best explainer videos I have seen in a long time. A interesting take away is the prime BMS having a balancer that is always on. Should 1 cell reach 3.65V charging is stopped and reported as at 100% SOC. This is what I found with the JK tied to SVolt 184Ah cells over the weekend. Cells were top balanced before discharging and during recharge 2 cells went higher than the rest.
October 20, 20232 yr Author 4 minutes ago, Scorp007 said: A interesting take away is the prime BMS having a balancer that is always on. Should 1 cell reach 3.65V charging is stopped and reported as at 100% SOC. This is what I found with the JK tied to SVolt 184Ah cells over the weekend. Cells were top balanced before discharging and during recharge 2 cells went higher than the rest. Yeah, Andy has some good videos about those active balancer add-ons that are no good if left permanently on.
October 20, 20232 yr 44 minutes ago, WannabeSolarSparky said: Andy continues to amaze me with his tests, saving us a ton of time with understanding how lithium iron phosphate batteries work. this is one of the best explainer videos I have seen in a long time. Yah, he very much confirms what I stated from observation in my thread "My own battery management". But in a rather complicated way.
October 20, 20232 yr what an informative clip. Thank you He does what manufacturers don't do, proper practical testing. Love his videos
October 20, 20232 yr Author 20 minutes ago, zsde said: what an informative clip. Thank you He does what manufacturers don't do, proper practical testing. Love his videos And it is quite good seeing how some of those suppliers respond to his testing and update their builds with some of his suggestions. It would be nice to see SA companies respond to constructive criticism like the Chinese ones do 🤪
October 20, 20232 yr Would love to see his testing by using those 4 batteries on the same Inverter in User mode without comms to see what the outcome will be.
October 20, 20232 yr Author 38 minutes ago, zsde said: Would love to see his testing by using those 4 batteries on the same Inverter in User mode without comms to see what the outcome will be. He has in previous videos connected most of his batteries of varying sizes in parallel and without comms and they work perfectly as most of the BMSes do what they are supposed to do. I myself also run without comms with my sunsynk inverter and have never had any issues in the few years I have had them and my batteries still stay nicely balanced all the time and discharge nicely to rated AH when they need to.
October 20, 20232 yr May be someone can explain why is Andy against the 4th battery that cut charging. When at 3.4V per cell lithium is at 100% SOC (rest) so why without showing each cell voltage and 1 or more cells at 3.65V to stop charging can he state the battery as a whole is not at 100% SOC? Surely getting the battery at rest would have been a better indication of SOC. Again by looking at all cells. Edited October 20, 20232 yr by Scorp007
October 20, 20232 yr Author 45 minutes ago, Scorp007 said: May be someone can explain why is Andy against the 4th battery that cut charging. He is not against that battery, he is against how they added on an active balancer that is always on. He has quite a few vids showing how ALWAYS ON active balancers are not good for the balancing and how it interferes with the bms. At the end of that video he mentions that the supplier of that battery brand is going to send him a neeeeee smart balancer to replace the dumb active balancer on that specific battery.
October 20, 20232 yr 5 hours ago, zsde said: Would love to see his testing by using those 4 batteries on the same Inverter in User mode without comms to see what the outcome will be. He hasn't got any comms in that test.
October 20, 20232 yr 48 minutes ago, WannabeSolarSparky said: He is not against that battery, he is against how they added on an active balancer that is always on. He has quite a few vids showing how ALWAYS ON active balancers are not good for the balancing and how it interferes with the bms. At the end of that video he mentions that the supplier of that battery brand is going to send him a neeeeee smart balancer to replace the dumb active balancer on that specific battery. Thanks. Did he then af any stage withdraw his remarks on the all in one JK BMS which he was full of praise when he tested it? Or did he later decide a always on active balancer is not a good feature? Sorry for all the questions but I just don't have the time to watch every video he makes.
October 20, 20232 yr 1 hour ago, Tinbum said: He hasn't got any comms in that test. Do you perhaps have the URL for that vid. I found the one with two Seplos with different capacities but with BMS comms. Maybe I am blind, but haven't found the one without comms
October 20, 20232 yr Author 1 hour ago, Scorp007 said: Thanks. Did he then af any stage withdraw his remarks on the all in one JK BMS which he was full of praise when he tested it? Or did he later decide a always on active balancer is not a good feature? Sorry for all the questions but I just don't have the time to watch every video he makes. These batteries are factory supplied batteries who all mostly use pace bmses, the last one he had issues with had the bms + the active balancer that is permanently powered on, which is the part he has issue with. This has nothing to do with the JK BMSES at all, he is one of the biggest JK BMS fans on the planet I think 🤣 As a matter of interest he just released a video on the new inverter style JK BMS
October 20, 20232 yr 57 minutes ago, zsde said: Do you perhaps have the URL for that vid. I found the one with two Seplos with different capacities but with BMS comms. Maybe I am blind, but haven't found the one without comms It's the first post.
October 20, 20232 yr 1 hour ago, Scorp007 said: Or did he later decide a always on active balancer is not a good feature? No active balancer that is on all the time is good as he says. The new Seplos active balancer has the same flaw!!!
October 20, 20232 yr Just now, Tinbum said: It's the first post. I was actually wanting the vid where he connects two batteries with different capacities to an inverter and uses them whilst discharging. Did find it. I think it's this one, unless @WannabeSolarSparky actually has seen another one.
October 21, 20232 yr 15 hours ago, zsde said: I was actually wanting the vid where he connects two batteries with different capacities to an inverter and uses them whilst discharging. Did find it. Looked at the entire video. Everything happened exactly as I expected. I have posted some time ago that you can parallel packs of different capacity as long as they are the same chemistry and the same number of cells. The test also confirmed that BMS do have problems to calculate SOC and do NOT communicate with each other - luckily by the way, each pack reacts individually. He also wondered like me witch of the two packs would communicate to the inverter and how would the inverter react. So I prefer not to have communication with the inverter. Let the charge management be done by the inverters MPPT based on battery voltage only. Concerning the balancing of the cells he observed pretty much the same as I have. The balancing feature built in the BMS is almost useless. It acts only on voltage way higher than recommended bulk charge voltage and would require to remain there for extended time in order to have any effect.
October 21, 20232 yr 27 minutes ago, Beat said: Concerning the balancing of the cells he observed pretty much the same as I have. The balancing feature built in the BMS is almost useless. It acts only on voltage way higher than recommended bulk charge voltage and would require to remain there for extended time in order to have any effect. But in Andy's case he was not happy with batt no4 which has a permanent active balancer that does not have to wait to start it's action. I would still like to see a good link not forum comments why one must wait for 3.4V before balancing starts as per most BMSes. What are the draw backs or consequences when starting earlier?
October 21, 20232 yr 18 minutes ago, Scorp007 said: But in Andy's case he was not happy with batt no4 which has a permanent active balancer that does not have to wait to start it's action. I would still like to see a good link not forum comments why one must wait for 3.4V before balancing starts as per most BMSes. What are the draw backs or consequences when starting earlier? Andy has made a few videos on that specifically . If you start earlier(in the flat part of the curve) it will unbalance the cells over time. You do not want to balance in the flat part of the curve.
October 21, 20232 yr 2 hours ago, Nexuss said: Andy has made a few videos on that specifically . If you start earlier(in the flat part of the curve) it will unbalance the cells over time. You do not want to balance in the flat part of the curve. Thanks @Nexuss Hope someone can add links as I know we have members saving links.
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