reach Posted August 16, 2020 Share Posted August 16, 2020 Hi, yesterday I took my V8 uphill. I took a 4km very steep trail uphill. This costed so little battery that, when I took the 12km way downhill, both, the app as well as the indicators on the wheel showed soon that the battery is full again. This started worrying me a lot: I know that an EUC can't turn break-energy into heat, so it all needs to go into the battery. Cool thing! But I don't know what happens on a long downhill road, when the battery is eventually full. Will it start to break "weaker"? Will it overheat? Will it suddenly throw me off? I ended up going super carefully. Half way down I met a friend (remarkable coincidence!) on the bike going uphill. So I joined him a few km back uphill chatting and for a few hundred meters, just for fun and out of curiosity, I pushed him and his bike uphill :-) This drained the battery enough that I felt comfortable. Does anybody know for sure what happens if I go downhill with a full battery? Other question: can it be that the battery indicator is bit of a hoax and it doesn't recuperate so much? In fact it really felt like a perpetuum mobile. Going uphill 4km, riding around on the mountain from peak to peak AND charging to over 100% downhill somehow sounds impossible. Quote Link to comment Share on other sites More sharing options...
meepmeepmayer Posted August 16, 2020 Share Posted August 16, 2020 (edited) 14 minutes ago, reach said: Does anybody know for sure what happens if I go downhill with a full battery? Depends on the wheel. Most (all?) will just beep/tiltback at you. It's not like they explode instantly, but you should definitely heed the warning immediately or I guess they would have to switch off eventually (when the battery is full and more power is coming in, it's the only choice). Until that point they won't behave any differently. There was a case where a V8 cut out downhill (rider fell on his ass, harmless) that could best (only?) explained by reaching a full battery. No warning, maybe because everything happened quickly. You can charge your V8 to fulll and just carefully see what happens if you go downhill with it. And go by the voltage/charge % in an app, not the imprecise display on the wheel, to see how full your battery really is. Edited August 16, 2020 by meepmeepmayer Quote Link to comment Share on other sites More sharing options...
StuartL Posted August 17, 2020 Share Posted August 17, 2020 11 hours ago, reach said: Does anybody know for sure what happens if I go downhill with a full battery? Ultimately one of five things will happen, the energy has to go somewhere: 1. The EUC has a way of converting the extra energy to heat. I'm not aware of any EUC which can do this. 2. The EUC deliberately under-charges the battery so that there is headroom for extra charge on a downhill stretch. This seems very possible but I wouldn't rely on it. 3. The EUC will warn you (tiltback, audible alerts, etc). I don't know which wheels do/don't have this alert. Ignoring this warning will cause one of the last two things to occur. 4. The EUC has battery over-voltage protection and will cut-out, causing a fall. 5. The EUC has no battery over-voltage protection and will cause overcharging of the batteries. This will, at best, reduce the lifespan of the batteries and, at worst, cause a battery fire. I'm guessing what I'm saying is that for your use case: Don't do it unless you can find a manufacturer who will stand by their product and guarantee that at least one of the first three options above will occur. Trusting anecdotal evidence on this forum (even my own) is very risky... Quote Link to comment Share on other sites More sharing options...
null Posted August 17, 2020 Share Posted August 17, 2020 If tou look at the current going in or out of the battery you can get an idea of what speed regenerates or is around zero sum / uses energy if you need that. Living on a hill it has been reassuring to at least have a rough idea of what’s going on and how to make the best of it. Quote Link to comment Share on other sites More sharing options...
Toad Posted August 17, 2020 Share Posted August 17, 2020 If you sail up a hill, then sailing down that same hill should not pose a problem (unless you recharge at the top). Translation of energy to motion on the way up, or motion to energy on the way down, is not perfect. A little bit is always lost. The unicycle is not a perpetual-motion machine. Quote Link to comment Share on other sites More sharing options...
reach Posted August 17, 2020 Author Share Posted August 17, 2020 14 minutes ago, Toad said: The unicycle is not a perpetual-motion machine. That's exactly what I wrote in my original question ;-) Quote Link to comment Share on other sites More sharing options...
MBIKER_SURFER Posted August 27, 2020 Share Posted August 27, 2020 My Nikola tilts back in this case. This happened to me once in exact this situation. Full battery - going downhill and breaking. 1 Quote Link to comment Share on other sites More sharing options...
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