ArieKanarie Posted August 3, 2021 Share Posted August 3, 2021 (edited) Hello, I sometimes leave my 16X on the charger at 100% to balance when I know there's a ride coming up. But every now and then when the 16X has been at 100% for around 3-4 hours or so it starts to slowly drop in voltage/%. Is this intended to not damage cells when they stay at 100%? I keep my charger on a smart plug so I can start charging while I'm at work and make plans to ride in the evening. Yesterday I knew my wheel was at 95% in the morning. Started "remote" charge 3-4 hours before the ride. When I wanted to leave the charger was green but my wheel was at 85%. I had to remove the charger from it's wall socket and power cycle my 16X for it to charge again (charger red) This has happened before when I balanced for 2 days because of a very long ride coming up. Charger green, wheel at ~65% or so.. Quite annoying but nothing I can't live with. Edit: I normally leave my wheel at ~60% charge when it's not in use and only charge to full when I know I'm going to ride. Edited August 3, 2021 by ArieKanarie 1 Quote Link to comment Share on other sites More sharing options...
..... Posted August 3, 2021 Share Posted August 3, 2021 (edited) I'm not exactly following you on what is going on? I do know that theres absolutely no reason to leave a wheel on a charger for days tho. My kingsong wheel pretty much shuts itself off when fully charged. I can unplug it and try to charge a 100% wheel, but nothing happens. I think the wheel doesnt allow you to charge it, unless its below a certain voltage. Its not much lower than full, but its something. I just leave mine fully charged as i dont let it sit for more than a week at a time. It is VERY troubling that you charged and 95% wheel for 3 hrs and ended up with 85% in the end. Watching a battery drop from full to 95% or so, is no big deal. Surface charge and all, no worries. Having one DISCHARGE while charging, is an entirely different matter. I'd ride it down a little bit, then fully charge and leave it once green for an hour or two. Perhaps do this while you are around. I'm not too keen on hearing people starting chargers from remote locations, but its your house, not mine. Edited August 3, 2021 by ShanesPlanet 2 Quote Link to comment Share on other sites More sharing options...
ArieKanarie Posted August 3, 2021 Author Share Posted August 3, 2021 20 minutes ago, ShanesPlanet said: I do know that theres absolutely no reason to leave a wheel on a charger for days tho. There is, if your BMS balances your cells only during charging, which is most of them. 21 minutes ago, ShanesPlanet said: I'm not too keen on hearing people starting chargers from remote locations, but its your house, not mine. There's a IP camera with motion detection and smart smoke detectors above my charging spot in my scullery. What I think is going on is that the charging can be shut off by the wheel once it is done. When it is done it stays on (since I can still connect with bluetooth), which will drain the battery slowly. But then the charging doesn't kick in again. Or maybe EUC world makes some calculating mistakes or something, even though voltage readings matched % more or less 1 Quote Link to comment Share on other sites More sharing options...
..... Posted August 3, 2021 Share Posted August 3, 2021 (edited) 10 minutes ago, ArieKanarie said: There is, if your BMS balances your cells only during charging, which is most of them. There's a IP camera with motion detection and smart smoke detectors above my charging spot in my scullery. What I think is going on is that the charging can be shut off by the wheel once it is done. When it is done it stays on (since I can still connect with bluetooth), which will drain the battery slowly. But then the charging doesn't kick in again. Or maybe EUC world makes some calculating mistakes or something, even though voltage readings matched % more or less Balancing takes an hour or two, not days. You are probably onto something. Leaving things connected can cause parasitic drains. I'd almost bet that once the charger is told to turn off by the smart plug, the connection is causing a discharge, tho slowly. Best would be to charge until full and break the charger connection it seems. I recall the 16x had a bug that made the wheel stay on after fully charged. Are you on the newest firmware? Good idea about the cameras and smoke detectors. At least you'll hear and see it happen. Chances of something happening are so damn slim thankfully. Just be sure to rid of any video before an insurance company asks for it. Edited August 3, 2021 by ShanesPlanet 1 Quote Link to comment Share on other sites More sharing options...
Chriull Posted August 3, 2021 Share Posted August 3, 2021 (edited) 54 minutes ago, ArieKanarie said: I sometimes leave my 16X on the charger at 100% to balance when I know there's a ride coming up. There should be no valid reason to do this. Most likely this is just "stressing" the li ion cells by trickle charging. As it seems balancing happens after the C(onstant)C(urrent) Stage ended. This is once the app shows "wrongly" already 100%. Once the green light starts on the charger with most charger/wheel combinations charging finished according to the cells datasheet! 12 minutes ago, ArieKanarie said: There is, if your BMS balances your cells only during charging, which is most of them. No, the final balancing happens after the charger is disconnected. More details on why charging after green light is not only not necessary but a bit stressy for the cells can be found here: https://forum.electricunicycle.org/topic/22109-passive-balancing-a-simulation/?do=findComment&comment=359303 Quote But every now and then when the 16X has been at 100% for around 3-4 hours or so it starts to slowly drop in voltage/%. Is this intended to not damage cells when they stay at 100%? Imho the 16x, or some motherboard/firmware combinations have some parts on when the charger is not detached. So they drain battery charge! So one has higher battery wear as they are discharged without any "use". Edited August 3, 2021 by Chriull 2 Quote Link to comment Share on other sites More sharing options...
Popular Post null Posted August 3, 2021 Popular Post Share Posted August 3, 2021 (edited) There is a KS battery drain bug or feature ( @Jack King Song didn’t seem to provide an answer) where basically the controller board stays on after the charge. It should resolve by power cycling it on and off. Edited August 3, 2021 by null 4 Quote Link to comment Share on other sites More sharing options...
The Brahan Seer Posted August 3, 2021 Share Posted August 3, 2021 32 minutes ago, Chriull said: No, the final balancing happens after the charger is disconnected. This doesn't make sense to me, forgive my ignorance but I thought balancing occurs continuously as its being charged? Could you explain to me how it actually balances after it has been disconnected? like the mechanism? I am aware there is passive and active balancing but that is as far as I know. Quote Link to comment Share on other sites More sharing options...
Chriull Posted August 3, 2021 Share Posted August 3, 2021 3 minutes ago, The Brahan Seer said: This doesn't make sense to me, forgive my ignorance but I thought balancing occurs continuously as its being charged? Could you explain to me how it actually balances after it has been disconnected? like the mechanism? I am aware there is passive and active balancing but that is as far as I know. As written, the explanation is in detail in https://forum.electricunicycle.org/topic/22109-passive-balancing-a-simulation/?do=findComment&comment=359303 . In short - It's mostly one cell (group) that's deteriorated first and looses capacity, has increased internal resistance, etc... This is the first that would reach the cell overvoltage threshold stopping the charge of the whole battery. So at ~4.2V the "balancing" resistor is put in parallel to let the voltage rise slower for this cell group. If charging is finished, this cell group gets discharged by the balancing resistor again to ~4.19-4.2V. If the charge happend without premature cut-off the other cells should be charged to nearly 4.2V, too. So the balancing happens in the beginning by bypassing current by the weak cells and then _after_ charging as these cells get discharged again to ~4.2V. 2 Quote Link to comment Share on other sites More sharing options...
The Brahan Seer Posted August 3, 2021 Share Posted August 3, 2021 Thank you for your explanation and the link, its starting to make more sense to me now and its much appreciated. So my next question is do you think when the green light shows on a charger it only turns green after the system has been balanced and not when it reaches 100% SOC. eg it takes say 5 hours to actually charge and 1 hour to balance after which green light shows after 6 hours? Quote Link to comment Share on other sites More sharing options...
Chriull Posted August 3, 2021 Share Posted August 3, 2021 46 minutes ago, The Brahan Seer said: Thank you for your explanation and the link, its starting to make more sense to me now and its much appreciated. So my next question is do you think when the green light shows on a charger it only turns green after the system has been balanced and not when it reaches 100% SOC. eg it takes say 5 hours to actually charge and 1 hour to balance after which green light shows after 6 hours? The led turns green once some current threshold is reached. This threshold is normally set by some internal trim potentiometer as described here: https://forum.electricunicycle.org/topic/2247-decrease-charging-time-5a-high-current-charger-mod/?tab=comments#comment-25662 . With some good faith one could hope this threshold is set to some sane values - as sometimes reported here from people measuring these threshold it is mostly quite ok. Specified in manufacturer datasheets for many li ion cells are some 50-60mA current threshold to stop charging. So this could be considered as 100% SoC according to the datasheed recommendations if the charger turns green at ~(50-60)mA per paralleled cell. But it also turns green if the cell is misbalanced and one cell group reaches the overvoltage threshold and the bms cuts off. So the green led has no correlation with the balancing state of the battery. 3 Quote Link to comment Share on other sites More sharing options...
mrelwood Posted August 3, 2021 Share Posted August 3, 2021 1 hour ago, The Brahan Seer said: So my next question is do you think when the green light shows on a charger it only turns green after the system has been balanced and not when it reaches 100% SOC. eg it takes say 5 hours to actually charge and 1 hour to balance after which green light shows after 6 hours? As @Chriull already replied, the charger doesn’t have the slightest clue about the BMS balancing process. And the charger doesn’t know if it has been unplugged or if the BMS safety feature has interrupted charging. The EUC chargers seem to turn green once the charging current drops below 300-700mA. The charging process itself isn’t affected by this. But because the current threshold is so high, it’s best to leave the charger plugged in for an hour or two after green. Leaving the charger in for longer than 4-6 hours after green either just keeps the cells at the very top of their voltage range and doesn’t let them set in and slowly damaging the cells, or does absolutely nothing if the BMS has interrupted the charge. 2 hours ago, ArieKanarie said: What I think is going on is that the charging can be shut off by the wheel once it is done. When it is done it stays on (since I can still connect with bluetooth), which will drain the battery slowly. But then the charging doesn't kick in again. Based on what I’ve read about the later KS wheels, I believe you to be correct. 2 hours ago, ArieKanarie said: Or maybe EUC world makes some calculating mistakes or something, even though voltage readings matched % more or less EUCW does have two battery % curves, and I guess the custom one could seemingly emphasize the post-charge KS drain. 1 Quote Link to comment Share on other sites More sharing options...
The Brahan Seer Posted August 3, 2021 Share Posted August 3, 2021 Thank you for the comprehensive replies much appreciated. I'm very slowly learning the idiosyncrasies of EUC ownership. Quote Link to comment Share on other sites More sharing options...
Tawpie Posted August 3, 2021 Share Posted August 3, 2021 (edited) 7 hours ago, ArieKanarie said: But every now and then when the 16X has been at 100% for around 3-4 hours or so it starts to slowly drop in voltage/%. As you noted, the 16x leaves its control board powered up (all LEDs on, bluetooth on) after the charger decides to remove charging voltage. This will 'drain' the battery until you power cycle the wheel so I'm not surprised to see your voltage drop in that situation. Later firmware (2.07 I think) does restart the charge if the charger is powered and connected AND the controller's measured voltage drops enough but I don't think it would restart in 2.02 and earlier. The later firmware also might shut down the control board after full charge and the charger is disconnected—mine makes that speaker whump sound with brief headlight flash on 2.09... I don't think it did that on 2.02 but don't remember (senioritus). On EUCW, don't use the custom battery percentage—it's misleading. I think it might be an estimate of remaining range and is getting fooled because you're not really using energy immediately post-full-charge, but the voltage is dropping so it's assuming a higher consumption per kilometer. 7 hours ago, ArieKanarie said: I normally leave my wheel at ~60% charge when it's not in use and only charge to full when I know I'm going to ride. This is how I've treated my batteries... 2000 miles and no noticeable decrease in range. The only thing I do different is when I do charge, I charge to charger cutoff (green light) plus 1 hour. Then I disconnect the charger and power cycle the wheel and do my best to ride it down below 90% in the next 24 hours. Edited August 3, 2021 by Tawpie 1 Quote Link to comment Share on other sites More sharing options...
ArieKanarie Posted August 5, 2021 Author Share Posted August 5, 2021 I see. I am used to other PEVs where the BMS does balance when it is nearing 100%. Onewheels do this and also DIY esk8's with DIY battery packs. Next time I will remove the charger max 1 hour after it turns green, the first bit of power drops quickly anyway. Maybe I can somehow combine a watt meter + smart socket to automatically shut the charger off when there is almost no power being used by the charger. Everyone talks about firmware 2.07 while my wheel is on 2.03. There are no updates available for me though? not in EUCW nor the Kingsong app. 1 Quote Link to comment Share on other sites More sharing options...
ArieKanarie Posted August 6, 2021 Author Share Posted August 6, 2021 On 8/3/2021 at 5:16 PM, Tawpie said: On EUCW, don't use the custom battery percentage—it's misleading. I think it might be an estimate of remaining range and is getting fooled because you're not really using energy immediately post-full-charge, but the voltage is dropping so it's assuming a higher consumption per kilometer. Wow you were right lol. I switched back to standard since my first ride ever on my 16X and I think I might have more range than I thought! "Normally" I would only have 65km per charge, but with standard I was at 50km at 50% yesterday.... Time for a rangetest Thank you Quote Link to comment Share on other sites More sharing options...
FinRider Posted August 6, 2021 Share Posted August 6, 2021 Just pitching in with my 2 cents.. my S18 has the same "feature"... seems to be the same for all KS wheels. Once the charge is complete and the led turns green, power cycle the EUC to stop the "phantom" drain. Quote Link to comment Share on other sites More sharing options...
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