## how efficent is your ebike

Get real world experience and user feedback on the electric bicycle products.
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Watt Hours is amp hours x volts, so a 48v 18ah pack would have 864Wh. Of course for an accurate measurement you have to measure real time voltage and current since high discharge rates lowers useful battery capacity due to voltage sag and cell heating.

Edit: forgot to add the hour part. fixed now
Last edited by Lowell on Sat May 26, 2007 2:57 pm, edited 2 times in total.
Lowell
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Location: Vancouver

geoff57 wrote:Hi all
Looks like I have opened up a hornet's nest when I started this thread.
It still looks like there is confution as to the item on test, it's is not the motor that is on test but the whole bike with rider.
So as not to be a closed to other ideas could somone please explaine just what the term watt/hours is and how it is calculated so I can see if it is a statistic that should be used in this I am open to ideas.

Opening up any topic of comparison 'round here is like stirring up a hornet's nest, but its all in good fun.
That is, untill someone forgets to sacrifice a hub motor to Volcano Boy, then it turns ugly.

A Watt hour is one watt for one hour. The reason its used most is because regardless of amps or volts, watt hours remains a constant. That's because 1 watt is 1 amp at 1 volt, and is figured at Amps X Volts.
that means 10 volts at 1 amp is the same watts as 1 volt at 10 amps. in both cases, its 10 watts.

Drunkskunk
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Location: Dallas, Texas. U.S.A.

Most of the watt hours per mile are figures given are unaccurate. Knowing the free spin watts help.Secondly the given figures on round trips WITHOUT pedaling and average trip speed on a given trip one can see most of the whole picture once the total weight is given. Trips up hill give the real figures to see how efficient the total system works.Once up hill figures are caculated the down trip frigures are free! unless your hub motor don't coast worth a dam.The average round trip speed in ANY hill grade or wind condition will tell the worst average round trip wattage used with excesive weight espaisally IF the motor performed many miles with a 100 lbs of battery weight UP HILL. These FACTS have been ttested for many more years than hub motors have been even available.So start testing with REAL figures to be somewhat creditable.All in good fun but honestly will help.Videos of the complete trip dont lie.
Last edited by EbikeMaui on Mon May 28, 2007 12:16 am, edited 1 time in total.
Efficiency and longevity Rules!

EbikeMaui
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EbikeMaui wrote: Trips up hill give the real figures to see how efficient the total system works.

It is a good test of efficiency, but maybe not the whole story.

Most EVs for sale provide at least:

X max speed @ x range

Y max range @ y speed

0-Zmph @ z seconds

Vehicle weight @ test conditions

Have a Nice Day,

TD

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TylerDurden
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Location: Wear the fox hat.

TylerDurden wrote:
EbikeMaui wrote: Trips up hill give the real figures to see how efficient the total system works.

It is a good test of efficiency, but maybe not the whole story.

Most EVs for sale provide at least:

X max speed @ x range

Y max range @ y speed

0-Zmph @ z seconds

Vehicle weight @ test conditions

Max contionus grade is a must if you don't want to get stuck with a burned up system.
Efficiency and longevity Rules!