The whoosh Predictor

[neptune]

On the Woosh site, is a predictor that shows the ranges that can be expected from batteries of different Amp hour batteries. I know that battery range is a notoriously difficult thing to predict. In the case of a 15Ah battery, the map shows that a commute to a point 15 miles from home is the maximum possible. That is a total mileage of thirty miles. Yet on the same site, a Scirroco Two, with 15 Ah battery has a claimed range of up to sixty miles. How can that be? There are more questions than answers.

Is the thirty mile figure the range without pedal assistance? Is that thirty miles on the flat, or in hilly terrain? What am I missing here? Anyone got any ideas please?

 

[trex]

range is given for near ideal condition, sunny, no headwind, zero gradient, rider puts in a reasonable amount of pedalling.
For example, the Kalkhoff Agattu i8 HS that CL wants to buy is fitted with 36V 15AH (540WH) is quoted with a range of 100 miles in ECO mode on a full charge. That's 5.4WH per mile. Another example: KTM Macina Race 29 is supplied with a 400WH battery, is quoted with a range of 75 miles in ECO mode, also 5.4WH per mile. The Woosh Sirrocco 2 is supplied with either a 10AH battery or a 15AH (540WH) battery. Woosh quote 50-60 miles for the Sirocco 2 with 540WH battery, 9WH to 11WH per mile. Of course the Kalkhoff and the KTM are not twice as efficient as the Sirocco 2, just that Woosh gives a more realistic range estimate.
Also, throttle can make people lazy. Perhaps Kalkhoff and KTM make you put in 40% of the energy required while Woosh expect you to use the throttle a bit.
The ebike emulator at ebike.ca shows clearly that average consumption depends very much on speed. At 10mph, you need 70W (7WH per mile), at 15 mph, you need 175W (11.6WH per mile). So, it looks like the Woosh estimate is more realistic.
The Predictor on the Woosh website is a tool to estimate battery consumption to go from A to B and back again at 10mph and at 15mph. For example going from the Woosh Cambridge shop to Newmarket (17.4 miles)


Cambridgeshire is pretty flat, still, you climb 140m on the way to Newmarket, a bit less (119m) on the way back.
The average consumption is 11.3WH per mile at 10mph, 13.5WH at 15mph. The Woosh Predictor divides the itenerary into small segments, calculates the battery consumption in each segment taking into account the target speed and the local gradient. It also highlights where the steepest bits are.
You can see how it's done by reading the Javascript on the web page.
The Predictor gives a more realistic estimate (11.5-13.5WH per mile depending on average speed) than the 5.4WH per mile for the Impulse motor or the Bosch motor.
Woosh use the same calculation to make up their motor performance charts, it's a sort of e-bike emulator for their bikes, similar to the e-bike emulator on the ebike.ca website but simpler, without the torque plot.

 

[neptune]

@trex. Many thanks for that comprehensive reply.Incidentally, it would be interesting to know how many watt hours per mile would be needed to to pedal an unassisted bike per mile. That would enable one to calculate what rider input would be needed to bring the battery load down to , say 6 watt hours/mile.

For some time now, I have been considering buying a new electric bike.I have an old lead acid powered bike, but the batteries are about worn out, so I only use it around town. My circumstances are untypical. I am fairly light at ten and a half stone. As I live in the fens, I very rarely ride on hills. I am into pedaling, and ride at least ten miles a day unassisted, sometimes doing a thirty mile trip in a day.

A city I like to visit sometimes is Lincoln, thirty three miles from home. Using the National Cycle route 1, it involves no more than thirty feet of climbing. On many occasions, I have done the trip one way, returning by train. I am considering how an ebike would fit into a trip like that. With a 15 AH battery, and supplying 50% [or less]of the input energy by pedaling, perhaps I could expect to do the journey both ways?

If I stayed in Lincoln for about four hours, and found a charge point, I could at least partly recharge before returning. Occasionally, I could possibly stay over night. I suspect that even a couple of hours recharging would help.Any thoughts/opinions? Another thing that would help, is that I would be quite happy at 10 MPH most of the time, as that is my usual "no wind" pedaling speed.

 

[Deleted member 4366]

That's dead easy. Any of the route loggers will give you that. They tell you how many calories. I Calorie (with a big C = 1000calories with a small c) = 1.163 Wh

 

[trex]

@trex.
A city I like to visit sometimes is Lincoln, thirty three miles from home. Using the National Cycle route 1, it involves no more than thirty feet of climbing. On many occasions, I have done the trip one way, returning by train. I am considering how an ebike would fit into a trip like that. With a 15 AH battery, and supplying 50% [or less]of the input energy by pedaling, perhaps I could expect to do the journey both ways?

you can ride to Lincoln and back (66 miles) on throttle alone at 10mph, piece of cake for a 15AH battery. At 15mph: you'll need to put in a bit of pedalling but still perfectly OK. No need to bring the charger with you.

 

[axolotl]

Loving the Whoosh predictor but I now realise a 15 A/h battery is going to be a bare minimum rather than a nice-to-have. Getting to work should be doable on pretty much any bike, but getting to college will take a whopping 490 W/h for the round trip. According to Whoosh that's outside the range of any of their bikes

 

[flapajack]

The woosh predictor also said I cannot make a round trip commute of 37 miles with a 15Ah battery on the scirocco cd. I can make the trip twice on a full charge of a 400wh battery (11ah) using low power Eco mode and peddling. It gives a great workout too. It all comes down to how much work you want to put in but from what you said it should be easy.