Ampler Nova e-bike

[pete H]

I have just read a news article and thought it was an April fools joke.. It charges in three hours from a USB C charger? https://amplerbikes.com/en/e-bikes/nova#comparison
70 mile range too.

 

[Stefan Mikes]

If the charger is 140 W and the battery is just 336 Wh then it is nothing strange to charge in 3 hours. I would not like to buy this e-bike though. An unnamed hub drive in 2025?

Range is a bullshit figure, too. Switch the assistance off and you get infinity range.

 

[pete H]

If the charger is 140 W and the battery is just 336 Wh then it is nothing strange to charge in 3 hours. I would not like to buy this e-bike though. An unnamed hub drive in 2025?

Range is a bullshit figure, too. Switch the assistance off and you get infinity range.

 

[pete H]

I agree Stephan ! I'm very happy with my Vado SL

 

[Stefan Mikes]

@pete H: I've just made a calculation. You can skip the section below
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The long version:

As you cannot discharge the battery below 5%, the effective charge on the Ampler is 336 * 0.95 = 319 Wh. Ampler says the range is 70 miles or 112 km, aye? That gives the battery consumption figure of 4.55 Wh/mi or 2.84 Wh/km. Now, let us assume you can ride at average 13 mph or 21 km/h. You ride a mile in 0.0769 h (4.16 minutes) or it is 0.0476 h (2.86 minutes) a kilometre.

Let us divide the battery consumption factor by the time in which you ride a distance unit (mi or km). It is 4.55 / 0.0769 or 2.84 / 0.0476, giving 60 W of electrical power drawn from the battery. Now, the mechanical efficiency of the motor might be 80%, or 0.8. To match the advertised value of range, Ampler would assist you with 60 * 0.8 = 48 W of mechanical power,
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The short version:

• Ampler provides the rider with 48 W mechanical assistance to meet the range of 70 miles
• Vado SL will have the same range on the main battery if the Assist figure is set to 20%.

It tells you how little assistance Ampler e-bike actually gives the rider (or the 70 mi is just a fairy tale by the boys in Estonia). What they cannot provide though is the SL Range Extender

Busted.

 

[pete H]

Too many figures for my tiny brain I think it's a pretty ugly bike too.

 

[onlineaddy]

Too many figures for my tiny brain I think it's a pretty ugly bike too.

To each his own. I think Ampler bikes look great! Kudos to them too for advancing the industry. Wish we got them here in North America.

 

[Stefan Mikes]

The motor and the battery you know nothing about.

 

[harryS]

The simple calculation is to derate the advertised watt-hours by 20%. Then use your personal Wh/mile rating to figure range, For me, that number ranges between 8-10 WH/mile. For the 337WH 48V7AH battery in that ampoler, the advertised 336WH drops to 270WH, and I'm pretty surre I can get around 30 miles.

Perectly legal to call it a 336WH battery, as the industry definition is volts (48) times amp-hours (7). But that's based on lab tests, In the real word of ebiking, taking off 20% is a good figure.

I was a bit surpised by the claim of 3 hour charging off USB-C, but they're using a laptop chargers with PD rating, which is 20V and 5A max, not phone chargers, Sure, I been hiding in my garage testing my ebikje batteries, Don't know nothing about this new stuff from 2021, Yes, 3 hours is enough time.
.

 

[Stefan Mikes]

but they're using a laptop chargers with PD rating, which is 20V and 5A max, not phone chargers

They sell a 140 W charger with USB-C output.
In my calculations, I derated the battery with 5%. Your Wh/mi figure is rather high. If the Ampler provides 48 W mechanical (60 W electrical) than it is OK to say the range of that lightweight e-bike is 70 miles. Only riders do not expect the assistance that weak.

@harryS: Specialized Vado SL has a 320 Wh battery with the cut-off at 5%. Many riders ride it with the assistance OFF and only turn the assistance on when they counter a headwind or hills. I'd say the range of Vado SL in the standard ECO would be up to 40 miles.