Wh Per Mile

[Scottyf]

Hello All,
Quick question. Just wondering what you are averaging in Watt hours per mile.
Currently I hit around the 7-8WH per mile.

However this moring I managed becasue of the strong head wind to crank up 2.2amp hours for my total journey one way of 8.8Miles.
Normally I tend to chew up about 1.7amp hours. Just shows how much push bikes are not aero dynamically very good.

Just wondered what kind of consumption other are using.

Regards
Scott

 

[flecc]

My best is exactly 5 W/h per mile on a Kalkoff Agattu.*

My worst is 26.4 W/h per mile on an eZee Quando. This is due to the bike being single speed and the motor driving faster than pedalling nearly all the time, so moped like consumption. The same bike equipped with gears and efficiency improvements can manage under 11 W/h per mile in favourable conditions.

* Switching off power a few times for very short periods when conditions for unpowered cycling were very favourable.
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[NRG]

Best I've got from the Proconnect so far is 6.5Wh over some hilly terrain and with the bike in Eco power all the time IE: not switching power off.

On my Peugeot I can get 8Wh with an average speed of around 13mph and 14Wh with the average around 17mph or slightly less. Again this is with power on all the time in Pedelec mode not turining the motor off and only occasionally riding above the assist point...

 

[Scottyf]

Thanks very much, least this way it gives me a comparision that the bike isn't chewing up to much energy.

Suprising what a head wind can do though to slow you down and use more battery to maintain a steady speed.

One point it felt like I was hardly moving forward at all.

 

[Deleted member 4366]

I ca get zero watt-hours per mile as long as there's no hills or headwind. I only have to pedal over 15mph, which is easy now that I've fitted a bigger chainwheel.

 

[Scottyf]

What chain wheel are you currently on?

SR Suntour XCT, 48/38/28 this is mine currently, with rear Shimano, 14-28, 7 Speed.

Don't think it would be worth me going any higher than the 48 I don't think I have enough power to push through to an effecient leg rpm speed.

 

[Deleted member 4366]

52 teeth on the chainwheel and 14 on top gear and a 170mm crank. I have seven speeds and can cruise at about 15mph unassisted in 6th gear on the flat. I use top gear when there's a following wind or downhill. I'm not particularly strong, so you should be able to manage the same.
While I was counting the teeth I just noticed that my chain doesn't fit very well. It appears to have stretched (worn). I've done about 2000 miles on it. Is that normal or is it a bit premature?

 

[Bandit]

How are we measuring wh - from the battery or from the wall. We get about 10wh/mile from the wall from our e-Motions, but not knowing the efficiency of the charger I don't know what the "true" figure is.

As a comparison point, the electric buggy we're testing is managing about 120 to 150 wh/mile (from the Cycle Analyst on the buggy) when driven by electric cyclists, and 160 to 175 when driven by car drivers. We're hoping to be at Presteigne if you fancy a run.

 

[flecc]

From the battery in my case, and I think most do that.

Chargers can be up to 85% efficient in the best cases, but there are wide variations, so basing W/h on battery nominal content is probably best. Otherwise it would be all too easy for charger variations to distort the real world bike results.
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[Bandit]

From the battery in my case, and I think most do that.

Chargers can be up to 85% efficient in the best cases, but there are wide variations, so basing W/h on battery nominal content is probably best. Otherwise it would be all too easy for charger variations to distort the real world bike results.
.

Do you work it from "battery nominal content" by seeing how many miles it takes to exhaust the battery, or do most people have some kind of instrument like a Cycle Analyst?

 

[Scottyf]

I'm currently using a turnigy watt's up meter.
This tells me how much i've used during my commute and all i do is divide the amount of Watt Hours used by the milage I've completed.

Not entirly accurate as I have no speed but I know the route and worked it out via good old googe maps.

Mines also taken from the battery...

 

[flecc]

I use miles to exhaust the battery to the bike's preset cutout or to the lowest level indication, such as the fast flashing stage on the Panasonic system which means all is over within about a mile.

It's not worth trying for precision when there are so many variables. For example the rider contribution alone on an electric assist bike can make a huge difference, doubling range in some cases. This makes a nonsense of precision measurement, as does the vast variation in terrain, from very flat to extremely hilly.
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