oaschi Posted February 18 Share Posted February 18 Hi, I've recently cutout for the first time on my 100v Nikola. A few friends wanted to know how the wheel works so I tried demonstrating it for them and immediately nosedived after a few meters (lol). I accelerated pretty hard, but nothing that the wheel shouldn't be able to handle. EUC World showed 47% safety margin and 96% battery. How would I go about investigating the cause of this? Quote Link to comment Share on other sites More sharing options...
Aztek Posted February 19 Share Posted February 19 (edited) A simple overlean? You can overlean this wheel, can't you? Edited February 19 by Aztek Quote Link to comment Share on other sites More sharing options...
UniVehje Posted February 19 Share Posted February 19 It’s possible that you just leaned too much when showing off. It happens quite a bit. Another option is that one or more cells are damaged. You could check what the voltage is when charged full. Without smart BMS you then need to open the battery pack and check individual cells for voltage. If the battery seems to change to full 100,2 volts, then you could inspect the board for damaged mosfets or capacitors. Quote Link to comment Share on other sites More sharing options...
oaschi Posted February 19 Author Share Posted February 19 2 hours ago, Aztek said: A simple overlean? You can overlean this wheel, can't you? 1 hour ago, UniVehje said: It’s possible that you just leaned too much when showing off. It happens quite a bit. Another option is that one or more cells are damaged. You could check what the voltage is when charged full. Without smart BMS you then need to open the battery pack and check individual cells for voltage. If the battery seems to change to full 100,2 volts, then you could inspect the board for damaged mosfets or capacitors. Yeah that's possible. But doesn't a safety margin of 47% rule out an overlean? Will check the voltage and Board/mosfets today. Do I have to destroy the shrink wrap around the battery for that and buy a new one? Quote Link to comment Share on other sites More sharing options...
UniVehje Posted February 19 Share Posted February 19 51 minutes ago, oaschi said: Do I have to destroy the shrink wrap around the battery for that and buy a new one? Only open it if you are not able to charge to full voltage and really want to know which cell is damaged and know what you are doing. I don't recommend messing with the battery pack without proper knowledge and equipment. It's a serious fire hazard. If you get 100,2 volts, you probably have a good battery pack. If you have faulty cells in your pack, that could cause an overlean to happen easier than normal. If that's the case, you need a new pack. 1 1 Quote Link to comment Share on other sites More sharing options...
Chriull Posted February 19 Share Posted February 19 (edited) 2 hours ago, oaschi said: Yeah that's possible. But doesn't a safety margin of 47% rule out an overlean? At slow speeds the motor can use much more current than mosfets could survive. As you had your incident "after a few meters" it could be that the motor current limitation kicked in. So there was just some theoretical safety margin. Also apps get values only a couple of time a second reported - internal these values are computed and needed some hundred times a second. So for "fast and short" incidents like yours this reported values can differ notable from the real maximum values. And as written - by showing off it's much easier to cross limits by accident... 2 hours ago, oaschi said: Do i have to destroy the shrink wrap around the battery for that and buy a new one? I would not mess with the battery wrap just in because of this. If the battery charges up to the chargers no load voltage and keeps about this voltage for some days it should be most likely ok! Edited February 19 by Chriull 1 1 1 Quote Link to comment Share on other sites More sharing options...
oaschi Posted February 19 Author Share Posted February 19 @UniVehje @Chriull Thanks a lot for the info!! Now I'm a little less worried about randomly cutting out on my wheel. Should the voltage not be good I'll just get help from a friend who is an electrician. And the next time I'm showing off I'll try to take it easier 😂 1 Quote Link to comment Share on other sites More sharing options...
alcatraz Posted February 21 Share Posted February 21 Does anybody know if battery sag (like aging, imbalance) impacts safety margin? If it doesn't it might explain this. Quote Link to comment Share on other sites More sharing options...
Mike Sacristan Posted February 22 Share Posted February 22 The Nikola 100v has a phase amp limit of 200A which has been measured to ~197A. This makes it easy to skip through the magnets when torquing it. Phase amp limits are not shown in PWM. This is most likely what you experienced. If it is a standard 100V Nik with 2 packs then it is a 4p config and battery amps cap at around 56A. Here it is possible to get a high amp warning beep at the same time you are sliding on asphalt. However you are riding a 6P version and it is difficult to high amp overlean it. My friend Lukasz who rides an MSP MSS tried an RS HS. He got soft pedals at around 20-30kmh because of how hard he accelerated but he was able to parry. Purple Rider did the same on his Nik AR+ but overleaned and fell. The only time I overleaned my Nik was at a standstill on an upward slope. I got on, torqued and skipped through every magnet on the planet. And also that time the motherboard died.... I have done some playing with Freestyler firmware on an RS HS where we raised phase amps from 220 to 250. 1 Quote Link to comment Share on other sites More sharing options...
Timwheel Posted February 22 Share Posted February 22 I'd say the most likely is you've just overtorqued it. When riding the V12 and Nikola, I always feel the magnets skipping. It is especially true at low speed as no relative wind pushes against your lean to act as a damper for acceleration demand. First time I did it was also trying to demonstrate the V12 to a buyer, so there is a psychological effect of wanting to show the performance of the machine for peer-pressure, so might have accelerated harder than ever before as I did. It's even worse if you have anything other than hard mode enabled, as it leans with you, making your input even more challenging for the wheel. Also, PWM at very low speed and high load isn't a reliable datum, as electric motors tend to have non proportionnal behavior at those high load/low speed. Let's keep safe guys Tim 2 Quote Link to comment Share on other sites More sharing options...
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