Show HN: Long Range E-Bike

Post by jacquesm » Sat, Nov 13, 2021, 9:43 AM UTC

gpm wrote: post #462

m0zg wrote: post #459

Earlier quoted context omitted.

I hope you realize you're one pebble or pavement imperfection away from breaking every bone in your body at those speeds.

At those speeds bikes are incredibly stable. The only way a pebble of pavement imperfection will harm you is if the bicycle fails mechanically (e.g. a wheel folding in on itself). I'm pretty sure that the risk of being hit by or hitting a vehicle is multiple orders of magnitudes higher. Which isn't exactly better, but let's at least worry about the correct sources of danger.

Post by jacquesm » Sat, Nov 13, 2021, 9:46 AM UTC

CRConrad wrote: post #524

jacquesm wrote: post #423

Earlier quoted context omitted.

Electric moped that works like a bicycle.

Still, the "mo" in "moped" comes from "motor". It's a vehicle with a non-human power source, just like a car. So I find it kind of weird that they're often allowed in bike lanes, especially where those are separated from pedestrians by just a painted line on a sidewalk (or sometimes even worse, explicitly mixed in with them!).

Post by jacquesm » Sat, Nov 13, 2021, 9:49 AM UTC

awakeasleep wrote: post #460

jacquesm wrote: post #91

Earlier quoted context omitted.

Yes, that's at 5% state-of-charge, which is a bit low. If you charge up to 100% and discharge to that cut-off point you will get 300 to 400 cycles out of your battery. If you go from 80% state-of-charge down to 20% then you can get thousands of cycles out of your batteries. That's one of the reasons I designed that pack as large as it is: to stay within the 80-to-20 range on a 100 km trip.

The “charge to 80%” advice isnt generally useful to PEV riders in 2021 It is true that a lithium _cell_ lasts longer when charged to 80%, but a _battery of cells_ must be “balanced” and PEV BMSes only do that balancing in the constant voltage stage of charging in the hours after the charger indicates the battery has been fully recharged. For anyone just learning about this, an unbalanced cell is usually the cause of…

Post by jacquesm » Sat, Nov 13, 2021, 9:55 AM UTC

chrismorgan wrote: post #490

jacquesm wrote: post #362

Earlier quoted context omitted.

It adds about 7 kg.

So that’s 7kg extra for your 2150Wh, over the original 500Wh battery? So around 250Wh/kg? I’ve been planning a velomobile that I can live out of, and I’ve been interested to observe that by the time you get to one kilowatt hour, I can’t find any Li-ion batteries at all: they’re all LiFePO₄. https://au.renogy.com/renogy-smart-lithium-iron-phosphate-ba... is then about 1280Wh (12.8V/100Ah) for 11.8kg, 110Wh/kg, around…

Post by jacquesm » Sat, Nov 13, 2021, 10:03 AM UTC

chrismorgan wrote: post #487

jacquesm wrote: post #175

Earlier quoted context omitted.

They are super dangerous too. Very low to the ground, nearly invisible from the perspective of a motorist and far harder to overtake with on narrow bike paths than regular bikes. We have a couple of them near here, also a few battery assisted ones. The velomobile would be an ideal vehicle if everybody rode one.

I haven’t yet ridden a velomobile (though I may purchase one soon and am planning on building one for riding round Australia and living out of for a year or so), but I’ve been riding a recumbent tricycle (Greenspeed GT3 Series II) since 2014, including various touring in Australia (Victoria and some South Australia), America (through California, and from St Louis to Philadelphia) and New Zealand (Auckland to Kaikoura…