Range on a New 500mAh Bosch

Wander

Esteemed Pedelecer
Aug 8, 2013
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Just charged it
Turbo 24 emtb 27 tour 38 miles
Not impressed
That's not an accurate indication of what you get in practice. The Bosch system guesses at the range left based on the last mile or so. So if your last mile home was downhill with minimum pedalling the range could easily say 100 miles+. If the last mile was completely uphill with pedalling hard & max assistance the range shown will be very low.
 
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D

Deleted member 22539

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Just found this thread after a week with my Cube with Cx performance 500 and two runs of around 30 miles and I’m really disappointed with the range.
Mostly old railway paths so no big climbs and not on turbo at all pedalling with purpose must of the time.
Just charged it
Turbo 24 emtb 27 tour 38 miles
Not impressed
Hi
Doesn’t sound right
I average around 35 -40 pure off road miles between eco and tour with around 3800 ft of climbing still with last segment on battery meter how much is left I don’t know as I’ve never flattened it
I have read thou that some are moaning about emtb mode sucking more out of the battery but I can’t comment as I don’t have it
Have you tried it in eco to see how it compares with not much climbing
 
D

Deleted member 4366

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Hi
Doesn’t sound right
I average around 35 -40 pure off road miles between eco and tour with around 3800 ft of climbing still with last segment on battery meter how much is left I don’t know as I’ve never flattened it
I have read thou that some are moaning about emtb mode sucking more out of the battery but I can’t comment as I don’t have it
Have you tried it in eco to see how it compares with not much climbing
They're interesting statistics. Let's do some maths:
to lift 1N 1m it takes 1 joule of energy, so to lift 100kg 3800ft takes
100 x 9.81 x 1158 Joules = 1,135,998 Joules, which is 316 watt-hours

The battery conversion to motive power is about 0.7 (optimistic) efficient when you add controller losses, motor losses and drive-train losses, so the battery would have to supply 451 wh for just the climbing, and only on a smooth surface. Any rough stuff and that would go up substantially. I would guess that most of the time going down-hill, the battery wouldn't need to supply any power. On the flat on eco setting, I'd estimate about 50w, so that works out (with a 500wh battery) one hour riding on the flat to add to the hill-climbing.

None of that includes the power you add yourself by pedalling, but neither does it include all the wind resistance losses and friction/rolling resistance losses, which added together are probably equivalent to your pedal power.

To summarise, it looks like your results are pretty close to the theory, so we can say that a 500wh battery will allow you to climb around 1km provided that you keep the motor more or less in its efficient zone and provide enough power yourself to overcome the resistances of the same ride as if it were flat.

The difference in power required between riding a full suspension MTB with 3" knobbly tyres on a rough track and a trekking bike with thin 700c tyres on smooth tarmac are going to be chalk and cheese.

The Bosch range calculator has a lot of variables to give reasonable estimates, but it doesn't take into account any hills, nor rough surfaces or really big tyres. From the above calculations, you can see that a 75kg rider needs to deduct around 30wh from the battery for each 100m he climbs, which is 7.5% and around 10% if you're 100kg.

On the flat, a 100kg rider would get 52km range in tour mode, or 46km with 100M climbed, so deduct 10% for 100m climbed and another 10% for not smooth road, which leaves you with 42km or 26 miles. That would go up to 29 miles for a 75kg rider.

https://www.bosch-ebike.com/en/service/range-assistant/
 
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Gubbins

Esteemed Pedelecer
The Bosch display can confuse matters.. if it shows 2 bars left, it won't go down to 1 bar until it hits 19% so your 2 bars can be anywhere between 20 and 39% which is quite a big variance. The Yamaha display also shows the actual percentage so is much easier to gauge remaining battery.
 

Nev

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May 1, 2018
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Terrific post d8veh thanks for writing it. I need to read it again to make sure I take it all in, but I really like posts like this, keeps the old grey matter ticking over.
 

soundwave

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May 23, 2015
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Francis Albert

Finding my (electric) wheels
Mar 19, 2018
20
5
63
Manchester
Crikey I go out on a ride and come back to this
Thanks for the great replies
Ok so just done 33 miles on the Derwent walk 16.5 up and when I say up it’s a very gentle incline tea and sausage sarnie then turn round and come back flat or slightly down hill.
Used mostly tour occasionally emtb and downhill eco or off...never turbo.
It lost a bar after 5 miles then another after 10 then a third after another 10 so figure I have 1.5 left
It is saying 8/9/11 left so range looks like 40 on a very light run.
Was expecting more as the bloke in the bike shop was quoting much higher figures
Maybe it will improve after a few more charges.
Right I’m going to read that mathematical reply again
Cheers everyone
 

Nev

Esteemed Pedelecer
May 1, 2018
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Maybe a bit less on top of Snowdon.
It was only recently that I found out you are allowed to ride a mountain bike up Snowdon. Richard Parks did it as part of his Extreme Wales series on the BBC. I think you are only permitted to use one route and you have to stick to certain times of the day (7pm to 7 am I think). I don't yet have the fitness to tackle something like that but perhaps in a couple of months I might give it a go, provided electric assist mountain bikes are permitted.
 
D

Deleted member 22539

Guest
Crikey I go out on a ride and come back to this
Thanks for the great replies
Ok so just done 33 miles on the Derwent walk 16.5 up and when I say up it’s a very gentle incline tea and sausage sarnie then turn round and come back flat or slightly down hill.
Used mostly tour occasionally emtb and downhill eco or off...never turbo.
It lost a bar after 5 miles then another after 10 then a third after another 10 so figure I have 1.5 left
It is saying 8/9/11 left so range looks like 40 on a very light run.
Was expecting more as the bloke in the bike shop was quoting much higher figures
Maybe it will improve after a few more charges.
Right I’m going to read that mathematical reply again
Cheers everyone
If it doesnt improve something is wrong , it definately needs keeping an eye on
Dont suppose you know anyone with a battery you can swap for a couple of rides :)
 
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anotherkiwi

Esteemed Pedelecer
Jan 26, 2015
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My longest ride with a 375 Wh 10.4 Ah bottle battery (Samsung 26F):

Mxus XF08 with Shimano Mega-Range freewheel, 48 tooth chainwheel and 26" wheel with Michelin fat slicks (1.95" ?), steel frame, no suspension

zarautz_st_jean.png
59.3 km, 515 m climbing + ride to the station, 14 km and 164 m climb
for a total of 73.3 km and 529 m climbing. The battery went flat at 72 km so the last 1.3 km was under my power alone.

d8veh posted this wonderful page the other day, it explains a lot: http://users.frii.com/katana/biketext.html An e-Mtb = more rolling resistance because of tyres and suspension + more air resistance because of upright position.

Looking at the above I would probably get well over 100 km from a Bosch powered trekking bike with slicks and a 500 Ah battery.

Some more reading:
https://www.sheldonbrown.com/rinard/aero/formulas.htm
https://www.sheldonbrown.com/rinard/aero/aerodynamics.htm
 

Francis Albert

Finding my (electric) wheels
Mar 19, 2018
20
5
63
Manchester
If it doesnt improve something is wrong , it definately needs keeping an eye on
Dont suppose you know anyone with a battery you can swap for a couple of rides :)
I will.
Three charges and no more than mid 30’s is not long enough for me!
Yes I do know someone I could ask...I will post results.
 

Doomanic

Pedelecer
Dec 7, 2017
214
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uk
Best I've seen so far is 28 miles and 3500ft of climbing in Eco. 2 miles range remaining. Tour gets me 20-22 miles, eMTB 16-22. Never done a full ride in Boost but I'd surprised if it made double figures.
 

Trevormonty

Esteemed Pedelecer
Jul 18, 2016
1,135
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Crikey I go out on a ride and come back to this
Thanks for the great replies
Ok so just done 33 miles on the Derwent walk 16.5 up and when I say up it’s a very gentle incline tea and sausage sarnie then turn round and come back flat or slightly down hill.
Used mostly tour occasionally emtb and downhill eco or off...never turbo.
It lost a bar after 5 miles then another after 10 then a third after another 10 so figure I have 1.5 left
It is saying 8/9/11 left so range looks like 40 on a very light run.
Was expecting more as the bloke in the bike shop was quoting much higher figures
Maybe it will improve after a few more charges.
Right I’m going to read that mathematical reply again
Cheers everyone
You never stated your speed, but given your in tour I'll guess 15-16mph. Try dropping it back around 12mph and keep it in eco, should be good for over 50miles on gentle terrain.
Faster you go more power is needed.
 
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