Miko.cz Posted July 29, 2022 Share Posted July 29, 2022 (edited) guys whats your maximum Voltage on KS-S22 production version? After full charging (rLED) with 1h balancing time (gLED) I still have about 124,8V in system and 125,2V both batteries. Power on power supply input is less than 2 Watts (I see in my power graph from Shelly wifi socket one moment step down from about 85W to 2W), EUC doesnt show any charging. Graph is from 2nd try of charge (after short ride), but same max Voltage as before the ride. Balancing on my old KS-16S was done with slow drop from 20W to 4W with 4x smaller battery and without noticable step down. Faulty power supply? (same issue was in pre-production) Edit: and EUCWorld "Počet plných dobití" = Count of full charges is ZERO (I tried to fully charg twice). Edited July 29, 2022 by Miko.cz added info about count of full charges Quote Link to comment Share on other sites More sharing options...
chanman Posted July 29, 2022 Share Posted July 29, 2022 I would check the charger voltage, sounds like it might not be up to spec. Quote Link to comment Share on other sites More sharing options...
SorenStarr Posted July 29, 2022 Share Posted July 29, 2022 Charged my S22 for the first time last night and now the tail light and battery meter screen are stuck on. When you turn off the wheel it just turns itself right back on! Also only charged up to 124v on my wheel too. 3 Quote Link to comment Share on other sites More sharing options...
Miko.cz Posted July 30, 2022 Author Share Posted July 30, 2022 Thanks guys. I just find that I have BMS fw 2.07, but actual is 2.10, so I updated it and will see next charging. I missed that information because KS app informed me about new fw for mainboard automatically, but for BMS It was necessary to check it manualy. 1 Quote Link to comment Share on other sites More sharing options...
Luis Ch Posted August 6, 2022 Share Posted August 6, 2022 Hi! Were you able to solve the issue? Right now I'm getting about 125.5V then stops charging and no balancing. 1 Quote Link to comment Share on other sites More sharing options...
Miko.cz Posted August 6, 2022 Author Share Posted August 6, 2022 Hi, not yet. Still have 70% battery left. Too busy :/ Maybe tommorow Ill be able to use it more and then recharge it for the first time on BMS 2.10 Quote Link to comment Share on other sites More sharing options...
Miko.cz Posted August 8, 2022 Author Share Posted August 8, 2022 (edited) So I have charged from 50% to 100% battery with main fw2.22 and BMS v2.10. Total distance of all rides on EUC: 76km. Charging has been ended again at 124.5VDC (EUC signalized full, power supply rLED->gLED and intelligent power socket shows 80±W->2W jump down in power drain). Difference from previous try is that BMS now shows 100% battery and full capacity remaining (with older fw there were just probably different calculations) I have sent question to my distributor. Edited August 8, 2022 by Miko.cz Quote Link to comment Share on other sites More sharing options...
Miko.cz Posted August 16, 2022 Author Share Posted August 16, 2022 I would like to ask more S22 owners to check their Voltage after charging. Please share any number you have. Thanks! Quote Link to comment Share on other sites More sharing options...
MetricUSA Posted August 16, 2022 Share Posted August 16, 2022 You can open the charger and tweek the pot to 126 v but it is a very very tiny clockwise turn... Use the app to watch the change... Quote Link to comment Share on other sites More sharing options...
Miko.cz Posted August 16, 2022 Author Share Posted August 16, 2022 1 minute ago, MetricUSA said: You can open the charger and tweek the pot to 126 v but it is a very very tiny clockwise turn... Use the app to watch the change... thank you, I know, Seba posted how to do it about month or so ago, Marty have also YT video. What im looking for now is what is normal and safe. What does 124.xVDC means - only wrong calibrated charger or some prevention of whatever. Im also interested in what balancing really means at KS-S22 and if its somehow affected by this max Voltage issue. Quote Link to comment Share on other sites More sharing options...
Omikens Posted August 16, 2022 Share Posted August 16, 2022 Mine charges to ~125,5V according to the BMS and then charger turns off. Ater a while voltage drops to 125,2V and stays at that level. App says that the wheel is charged to 100% and shows 126V. Kingsong app in "BMS info" tab shows that cell 4 in BMS1 is in balance mode (thats the only cell that goes into the balance mode, and it happens every time I charge to "full"). 1 Quote Link to comment Share on other sites More sharing options...
Chriull Posted August 16, 2022 Share Posted August 16, 2022 25 minutes ago, Miko.cz said: What does 124.xVDC means - only wrong calibrated charger or some prevention of whatever. And/or a badly calibrated motherboard. 25 minutes ago, Miko.cz said: Im also interested in what balancing really means at KS-S22 and if its somehow affected by this max Voltage issue. KS seems to torn off charging by the mainboard - as you have recorded the power dissipation drop of the charger from 80W to 2W. Such a charge stop should be triggered by a charge current threshold. Some 50-60mA per paralleled cell - so very roughly around 200-250mA for the KS22 (did not look in an actual datasheet of the used cells). A great measure to increase battery safety (if made right). Balancing happens all the time from reaching the CV stage to this charge cutoff and finished afterwards, as reported here: 13 minutes ago, Omikens said: Mine charges to ~125,5V according to the BMS and then charger turns off. Ater a while voltage drops to 125,2V and stays at that level. App says that the wheel is charged to 100% and shows 126V. Kingsong app in "BMS info" tab shows that cell 4 in BMS1 is in balance mode (thats the only cell that goes into the balance mode, and it happens every time I charge to "full"). Each cell settles it's voltage a bit after full charge. Cell 4 at BMS1 seems to be the weakest and gets charged to a bit higher voltage as the others. So it gets discharged a bit after the charging process stopped, so all cells have the same voltage again. Does the 0.3V voltage drop happen during the time cell 4 is reported as charging? Should not really happen with a new battery - is hopefully just a bad coincidence of charger and voltage measurement inaccuracies. One could try to repeat some charge cycles as soon as cell4 is not reported anymore in balance mode if this helps for the next full charge. 2 Quote Link to comment Share on other sites More sharing options...
Elliott Reitz Posted August 27, 2022 Share Posted August 27, 2022 Originally I had 124V max charging on V1 prototype S20. But firmware upgrade after the fire switched something that stopped it from charging. I measured 20V difference between charger ground and battery ground. Shorted that out and it charged, but then whatever ground difference messed up BMS communication and/or the hall sensor communication (blame the controller). The 2nd V1 S20 I got from eWheels did even worse. It rode 20 miles to unloack on 1st charge, but never did recharge and falsely reported battery cell over and under voltage (but measured the pair by VOM and they were fine). AR replaced the batteries and motherboard with V2.22 firmware and V2.10BMS version. Thankfully that's working and charges to 125V. As for the 125V charge max vs 126V max rating I hope that means that a fully charged S22 can do maximum breaking without cutout like my V11 did. S18 used to beep over it till I killed its beeper. Oh and I put a beeper-kill-switch on my S20-V1/V2 from AR now. 1 1 Quote Link to comment Share on other sites More sharing options...
Miko.cz Posted August 27, 2022 Author Share Posted August 27, 2022 I would like to add something more, but all I have now is reponse from KS (some higher engineer) to reseller that "its normal" (translated from Chinese). So right now Im not doing anything to change charger setting and leave it to 125V, in case its just a safety headroom as @Elliott Reitz mentioned (or a bit less charging stress for batteries as they are not maxed, but it could be too low to make any lifetime benefit). Quote Link to comment Share on other sites More sharing options...
supercurio Posted August 27, 2022 Share Posted August 27, 2022 125V reported is due to voltmeter calibration inaccuracy. There might be some exceptions but it seems very common for S22 BMS to indicate -1V or deviate more than real. It also prevent proper balancing in most cases, which for now occurs only on cell groups reaching apparent 4.2V, which can be 4.24V instead it the BMS voltmeter is off by -1.2V like one of mine is. I plan to write a fully detailed analysis once I get my wheel back in order, as I got a ISO calibrated multimeter just for this purpose. 2 Quote Link to comment Share on other sites More sharing options...
Rawnei Posted August 28, 2022 Share Posted August 28, 2022 For some reason EUC World shows different (higher) cell voltages than soft tuner, soft tuner feels like the most accurate out of the 3 apps (king song app also). Quote Link to comment Share on other sites More sharing options...
Elliott Reitz Posted August 28, 2022 Share Posted August 28, 2022 PS: Its not the charger like it may have been on some of the earliest prototype wheels. My chargers both measure 127.1V with a 0.1% accuracy VOM (I have several of them). Internally it reports 125V while the charger is at 127V. The wheel stops taking a charge after it reaches its "max" State of Charge (SOC). 1 Quote Link to comment Share on other sites More sharing options...
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