alcatraz Posted October 29, 2019 Share Posted October 29, 2019 (edited) Had my first high speed (slow wheel - v8) faceplant. I guess it's my own fault for unlocking the maximum speed. What's weird is that it was on a slight (i mean really slight like 2% decline) downhill and even though I was riding the tiltback I wasn't going faster than I'd been going for several hundred km with the wheel unlocked already. It was just a normal commute and no joyride which I do sometimes climbing mountains etc. After I got up the wheel was off and it powered back on right away normally. I didn't ride it, because of the shock. It sustained some damage aswell so I thought better give it a better check. Anyway the wheel has been absolutely bomb proof for 10.000km until now. It's been speed unlocked by a mere 2km/h extra for 500km. The unlock may have changed the tiltback somewhat. It seems that I get the full speed for a longer portion of the battery charge than before. I can do 32km/h maybe all the way down to 60-70%. Originally it throttles down to 28km/h after reaching 75% thereabout. At the time of the crash I had maybe 75% charge left. My question is, considering the wheel has a lot of km on it. Is there anything electrically that I can check to kind of see if it's worn out or has some damage? I mean the wheel powers on. I'm going to remove the speed setting and go back to normal. What can I check on the motherboard? Mosfets? How to do that? Melted wires? Puffed up capacitors? The weather is cool nowadays so overheating is not really a suspect. After climbing mountains in the summer I've never been able to get to 5x degrees C. It's always 30-40 something. Thanks for reading and commenting. Edited October 29, 2019 by alcatraz Quote Link to comment Share on other sites More sharing options...
Popular Post houseofjob Posted October 29, 2019 Popular Post Share Posted October 29, 2019 Wow, hope you're ok. "Unlocking" such a weak 800W nominal motor wheel with only 2 parallel packs to support it is a no-no IMHO. Even if you were able to ride the tiltback at the faster speed before, you're playing with fire being even more closer to the high speed / overpower cutout threshold, especially for the unexpected overpower bumps at speed, etc., especially as the battery depletes and/or colder temps artificially reduce battery power. Check your MOSFETs and wiring for sure, but I'm inclined to believe it's due to the speed hack. 6 Quote Link to comment Share on other sites More sharing options...
Nic Posted October 29, 2019 Share Posted October 29, 2019 This kind of worries me a bit because you have an upgraded battery pack with 50% more current delivery and you are only going slightly faster than the normal max speed. The battery does weaken in cold weather, but you didn't say what the temperature was. Battery packs do wear out as they are cycled, so that is another thing to factor in. I think its best to just stick with the normal speed limits for safety reasons. Quote Link to comment Share on other sites More sharing options...
alcatraz Posted October 29, 2019 Author Share Posted October 29, 2019 The outside temp was maybe 10 degrees C. Yeah sure the hack could have aggravated the issue but I'm afraid it may have been the cause of some electrical components displaying fatigue/wear or something. Like a 20000km wheel might not be safe at even the standard max speed. Or lets say 5000km for a 100kg rider, stressing the circuits faster than a light rider etc. I'll check the mainboard tomorrow. Yeah I'm pretty sure it wasn't an "overlean" problem as the machine was going at this speed for few hundred km and didn't display any sluggishness at all, which I could clearly feel before the battery upgrade. Maybe it was a software bug or something. I haven't touched the firmware for 9000km so maybe it has become corrupted or something hmm. I'm curious about any possibilities, or suspicions you might have. I have a second V8 I can use for failsearching. Quote Link to comment Share on other sites More sharing options...
alcatraz Posted October 29, 2019 Author Share Posted October 29, 2019 A second note is I did recently change my charger. From original to a third party one. Can the other charger damage the mainboard you think? The output voltage is fluctuating a little when there is no load. When charging the output voltage is increasing stably. It's a 3A charger instead of the original 1.5A. Quote Link to comment Share on other sites More sharing options...
houseofjob Posted October 29, 2019 Share Posted October 29, 2019 25 minutes ago, Nic said: The battery does weaken in cold weather, but you didn't say what the temperature was. Sure it does, just not dramatically. But if you disable the default safety features of a stock, 800W nominal 2P wheel that already is at a disadvantage power-vs-spec-wise, every inch counts IMHO. BU-502: Discharging at High and Low Temperatures Quote Link to comment Share on other sites More sharing options...
alcatraz Posted October 29, 2019 Author Share Posted October 29, 2019 23 minutes ago, houseofjob said: Wow, hope you're ok. "Unlocking" such a weak 800W nominal motor wheel with only 2 parallel packs to support it is a no-no IMHO. Even if you were able to ride the tiltback at the faster speed before, you're playing with fire being even more closer to the high speed / overpower cutout threshold, especially for the unexpected overpower bumps at speed, etc., especially as the battery depletes and/or colder temps artificially reduce battery power. Check your MOSFETs and wiring for sure, but I'm inclined to believe it's due to the speed hack. My battery is upgraded to 20s3p LG MH1 cells. It's got a good balance (i check regularly). The voltage sag is noticeably less. It accelerates very cleanly at high speed. I'm a light guy too at 65kg. I never expected it to happen on a nearly flat road where power requirement isn't as high as when climbing a mountain. Climbing is when the limits of the original battery are obvious. After upgrading the wheel is climbing awesomely. I can't say for sure I wasn't using more than 800w. But I do know the wheel has been supplying more than that power before. Maybe it's a continuous vs temporary thing? Like I was at 800w for too long? Still doesn't make sense. I was going downhill and the tiltback was operating. 1 Quote Link to comment Share on other sites More sharing options...
Mono Posted October 29, 2019 Share Posted October 29, 2019 4 minutes ago, alcatraz said: I was going downhill and the tiltback was operating And what exactly happened then? The pedals dipped forward or backward or...? Did you hit something or...? Quote Link to comment Share on other sites More sharing options...
Nic Posted October 29, 2019 Share Posted October 29, 2019 (edited) 41 minutes ago, alcatraz said: ... I have a second V8 ... Problem solved then... Edited October 29, 2019 by Nic 2 Quote Link to comment Share on other sites More sharing options...
houseofjob Posted October 29, 2019 Share Posted October 29, 2019 1 minute ago, alcatraz said: My battery is upgraded to 20s3p LG MH1 cells. It's got a good balance (i check regularly). The voltage sag is noticeably less. It accelerates very cleanly at high speed. I'm a light guy too at 65kg. Ah, that would be better at 3P, but even then, I think there's a reason why all 800W nominal motor stock EUCs, brand regardless, do not go faster than 30kph typically. 1 minute ago, alcatraz said: I can't say for sure I wasn't using more than 800w. But I do know the wheel has been supplying more than that power before. Maybe it's a continuous vs temporary thing? Like I was at 800w for too long? Still doesn't make sense. I was going downhill and the tiltback was operating. No way to know unless you were tracking via Wheellog or similar. Quote Link to comment Share on other sites More sharing options...
alcatraz Posted October 29, 2019 Author Share Posted October 29, 2019 (edited) 6 hours ago, Mono said: And what exactly happened then? The pedals dipped forward or backward or...? Did you hit something or...? It felt like it switched off. It wasn't trying to catch my fall att all. From steady speed, (only enough lean to sustain it, no acceleration) to just dead, in an instant. Pedals went forward. I've tested the wheel's speed and the tiltback kicks in at 32km/h and the fastest it's ever shown is 32.6km/h (before). When riding with low power on an old 20s2p battery the reduction in power could be perceived/estimated as maybe 60-70%. Nothing like that here. From 90+ zippy feeling wheel to 0. Then it powers on normally afterwards. I'm wondering if I should switch mainboards as a precaution or? Did some kind of protection trip in the battery? I'm hoping I'll see some obvious damage so I have something to fix. 😯 Edited October 29, 2019 by alcatraz 1 Quote Link to comment Share on other sites More sharing options...
Nic Posted October 29, 2019 Share Posted October 29, 2019 I wonder if the BMS has over-current protection and cuts the power if it detects a potential problem? I am clutching at straws here, but the BMS would be working on the basis the battery is still 20s2p configuration. Quote Link to comment Share on other sites More sharing options...
alcatraz Posted October 30, 2019 Author Share Posted October 30, 2019 Mm, because it powers on I have a feeling there won't be any signs of obvious damage. There is simply a gremlin living inside it. I do not wish to go faster than ~30km/h for safety reasons. My instinct tells me that it's safer to have ample power reserves (although I'm not sure that was the problem, seemed like a glitch). So maybe getting a Kingsong 18L/XL and run it around 30km/h max would be super safe and dependable. Ks16s seems nice too. Quote Link to comment Share on other sites More sharing options...
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