Distance on battery

Electrically assisted bikes, trikes, etc.
ambodach
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Re: Distance on battery

Postby ambodach » 15 Apr 2018, 7:21pm

I have a GTech Sport which I inherited. I did not buy it myself but the previous owner died before getting any real use of it.
Today has been my first real test which is a bit disappointing. I got 21 miles and the red light is on. About 2 miles were on steepish hills which I struggle with on my usual pedal power bikes and about 6 or 7 miles were into a vicious headwind. The rest were flattish or with a tailwind. It is very nice to get a push on the hills and into the wind as well as being much faster than my usual pooter. Speed never really fell below 13 mph except on the hills which went down to 11mph. If I had bought this I would be a bit peeved I think but since it cost me nothing I can hardly complain too much.

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brianleach
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Location: Winchester, Hants

Re: Distance on battery

Postby brianleach » 16 Apr 2018, 7:31am

I don't know how the GTech works. Do you switch the power on and off or is it on all the time under 25?

If it was on all the time it was presumably using power even on the flat in which case I would have thought 21 was pretty good. As I said in my previous post I reckon I only get 12 to 17 k of use.

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horizon
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Re: Distance on battery

Postby horizon » 16 Apr 2018, 12:24pm

This is a very useful thread. Although I'm sceptical about health claims for ebikes, overall I think they are going to be the bike of choice of many people. Technically, I think the breakthrough (lithium-ion) is already there.

So what I'm getting from this thread is that with ebikes there is a trade-off: hills, wind, distance, battery size/weight, speed, luggage. You can choose any of these but not all at the same time. For touring, you might indeed want all of them. For commuting, the OP's experience actually puts ebikes in a good light - there and back with an overnight charge.
It's autumn in England with the trees turning golden. So we say leaves mean leaves.

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brianleach
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Re: Distance on battery

Postby brianleach » 16 Apr 2018, 12:34pm

I think that is absolutely right from my experience and the sales promotions are rather misleading.

Until battery life improves I rather doubt that they are much use for touring except for short distances. Having had heart issues recently I thought an ebike conversion would be a way of still being able to tour.

I now do not think that this is practical even with a spare battery. Leaving aside the weight charging two batteries overnight would be a challange.

Fortunately the heart issues have improved following what the press seems to describe as "heart surgery" so I have booked a weekend in France in July to see whether I am up to non electric touring!!!

I shall continue to experiment with my converted hybrid in the meantime.

hemo
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Re: Distance on battery

Postby hemo » 16 Apr 2018, 3:10pm

21 miles is pretty good considering the battery is only 5ah/180wh. On average a ride will use 10 - 20wh per mile, a regular fit rider less then 10wh per mile.

ambodach
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Re: Distance on battery

Postby ambodach » 16 Apr 2018, 5:31pm

My GTech is left on high power tho’ there is a lower setting which I have not tried yet. Interesting comments about distance but there is a poster who gets at least40 miles on his commute. Probably uses more pedal power and mebbe also a flattish road.

hemo
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Re: Distance on battery

Postby hemo » 16 Apr 2018, 6:26pm

How many of the 40 mile is in low power mode or with no power at all, other considerations are terrain, riding conditions, rider weight and cycling fitness. Because one rider can or says they can manage XXX miles from said bike and battery doesn't mean every one else can and in this case appears to be far beyond that many could manage for the acclaimed mileage & battery ah, though not impossible if you are determined enough and frugal with battery use.
Another aspect is age and overall general condition of any said battery, even though they maybe the exactly the same.

hemo
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Re: Distance on battery

Postby hemo » 16 Apr 2018, 6:45pm

ambodach wrote:My GTech is left on high power tho’ there is a lower setting which I have not tried yet. Interesting comments about distance but there is a poster who gets at least40 miles on his commute. Probably uses more pedal power and mebbe also a flattish road.


You need to try yours on low power to compare the same route/mileage, lower power will mean more effort from you in general as the controller will only ask for low power/amps discharge from the battery so in doing so will increase the range.

ambodach
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Re: Distance on battery

Postby ambodach » 17 Apr 2018, 2:41pm

Will not have the chance to try the GTech on low power on the same route for a few weeks for comparison as I am home now in a totally different environment. Will use it in my home town which has short steep hills where high power will be needed. Mostly will be only for distances of up to 5 miles at a time at most. Seems to me it would be good for someone doing a fairly short commute who needs a bit of assistance. For non mobile handling would certainly be easier than most ebikes as it is much lighter and getting up the steps to my house is no more difficult than a normal pedal bike.

skelo
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Re: Distance on battery

Postby skelo » 7 May 2018, 7:06pm

The honest answer to your question is, nobody really knows - all systems are different and performance depends on a whole lot of variables, type of bike, gearing, size of wheels, rider weight, speed, acceleration, terrain, weather, etc etc..... I have found that only trial and error can tell you how your own system will work.

Having said that, my experience is that I am a middle aged 17 stone disabled bloke on a recumbent trike I have a 250W Heinzmann hub motor in the front wheel operated by a torque sensor in the bottom bracket, with a 515Wh battery. it is good for 80km(50 miles) on the flat and I charge overnight.

Last summer I cycled it 2200km to Italy in pretty much all conditions. On the flat on a nice day it will do the 80km easy, as long as i keep between 16-20km/h, if it is wet and windy, the range drops to around 40-50km. If I cycle at 20-25km/h it will only do about 35-40km,

Hills obviously drain the battery quicker, but it is speed that is the killer. We did a 1500m climb in 22km and 30 degree heat which drained the battery (and me!) i can drain the battery in 25km on the flat going at full pelt.

For long distance I have considered carrying a second battery, but I am carrying enough 'timber' as it is! Charging every night is no hassle.

Hope that makes at least some sense

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willcee
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Re: Distance on battery

Postby willcee » 7 May 2018, 10:43pm

Having just rebuilt a road bike winter trainer Merckx alloy med frameset, carbon fork and added a powerful Bafang mid motor 48v 1hp bsob2.. had a battery built for it in N London by a skilled electronics guy rated at 14amp 48v... hoping for a useful 30/40 miles without having a load of weight in a very powerful battery, he used good Samsung cells and its 10.5 x 3 x 2.7ins size wise weight approx 6lbs and its now done approx 5 rides and is coming in before recharging showing 1/3 on the display meter and when checked around 41 to 46 volts.. the rides were 30ish longest 36.. and normally cycling on level 3 and 4.. my chum who has a new Orbea Gain 36v 6.7 amps is doing the same rides and again coming in with less than a 1/3 but still providing decent assist..hilly windy routes..maxing at just around 16 as his cuts at that speed..and me having the odd blast yesterday at level 9 on a hill thats a 'strava' and climbing on the pedals at 25/6 mph in front of a fit clubman who wanted to set the local record, alas he couldn't stay on me wheel the wind caught him ..whats strava??? will

reohn2
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Re: Distance on battery

Postby reohn2 » 8 May 2018, 12:05pm

Our Circe tandem with a 17ah 36volt battery poewering thenfront wheel,gets us around 30miles miles with some juice left (1 green light left out of 4)on mildly undulating terrain mostly on assist level 2 or 3 with the odd hill needing assist level 4 sometimes 5 on 8+% hills.
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willcee
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Re: Distance on battery

Postby willcee » 22 May 2018, 12:35am

On Sat past myself and a couple of chums did 38 miles on a sunny but windy day, it was into the hills the Antrim plateau, a ride known as Orra Lodge used in the past by the Circuit Of Ireland Rally, and the Tour of the North cycle race, climbing for maybe 4 miles, 1.5m descent then another climb of maybe 2.5m over the highest pass in Co Antrim and then a descent or perhaps 3 miles then another steep climb of 3/4 mile all into a strong 30 mph head wind , my battery was flashing at zero on some parts quite disconcerting as we had covered about 23 miles and still had some 15 miles to get home.. I had research that said the Bafang display was notoriously inaccurate it was like looking at a petrol guage on the red empty zone and hoping that it would last the journey. I rode with my own power for about 6 miles easily as we had the tailwind at that stage and when about 6 miles from home hammered it in level 5 and got home quickly with power and still strong . when charging the next day i metered the battery at 41.6 volts, had started with 55.6, so how far should i let it go down and is there any way of having a more accurate guage which would save my mind.. will

hemo
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Re: Distance on battery

Postby hemo » 23 May 2018, 9:20pm

Will I assume your battery is 48v 13s so max charge should be 54.6v, 40v cut off is about the deepest you should discharge. Even at 41.6v cells are at 3.2v each so tbh not much point in discharging any deeper.

francovendee
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Re: Distance on battery

Postby francovendee » 24 Jun 2018, 8:40am

Reading all this has made me decide to wait as long as possible before buying an ebike. Battery improvement hasn't yet reached the level I think needed.
I'm thinking a range of 100 miles on one charge would be the ideal.