best speed and angle for downhill regen.

[Lucas Alexander Oliver]

So I'm just curious what the best speed is when you're going downhill to get the most out of the regen on the battery?  How much of a decline is needed and whatnot?  

 

Also while we are talking about batteries... how much does your speed and riding style affect your distance capabilities.   ?

  

[Xoltri]

I was curious about this too, but even at 100% efficiency you don't get a lot of energy back.  A 100m drop in altitude with a 100kg rider/wheel combo would get you 27 Wh, again assuming 100% efficiency which is not possible.  My MSX has a 1600Wh battery, so it's minuscule in comparison.  

As far as speed/range goes, riding style and speed makes a huge difference.  As does head/tail wind etc.  If I was going for max range I'd probably set the speed at 20km/h tops and be very gentle on the acceleration.  But where's the fun in that!

[LanghamP]

There's a few threads on this forum, with nothing very definitive, but the gist seems to be around 15% for extraordinarily skilled riders under very specific conditions. Now WheelLog might say 30% or so, but I have my doubts it is that high.

If you go to the top of a hill, and roll down, WheelLog will jiggle around a lot, but -600 watts consumption (or 600 watts regeneration, mind the minus symbol) seems about the average. Presumably, the minus is showing regeneration (I hope!) of 600 watts into your wheel, but now I wonder that it's just some random number, put there by the programmer to play with us, because it's almost close enough.

Going up the hill in the same amount of time takes 1800 watts, so the 600 watt seems about right. So if you go up the hill once, and down there times (you walk up the hill twice, or rather I did thank you very much), then you should have the exact voltage and % you started out with. However, this doesn't seem to be the case; try six times and ride down once, so the energy efficiency must be somewhere under 15%. And this is on a good hill.

Try a steep hill, and the wheel uses energy by braking, or rather it is using energy by slowly lowering you down the hill.

Bottom line; wheels are almost always total loss, and only regenerate on those hills where your speed is just high enough that wind resistance balances out overspeed, but low enough that the wheel is NOT braking.

In contrast, eSkates and eBikes seem very energy effecient in regenerative braking, possibly just losing energy in shoving it into the batter.