Distance on battery

Electrically assisted bikes, trikes, etc.
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Audax67
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Re: Distance on battery

Postby Audax67 » 24 Jun 2018, 9:25am

A chum who has bored me stiff for weeks talking about eBikes sent me this:

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

He's finally ordered one so I've told him he's riding up front in future unless there's a following wind.
Have we got time for another cuppa?

hemo
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Re: Distance on battery

Postby hemo » 24 Jun 2018, 9:29am

ebike batteries can do 100miles it's just the pack size and ah/wh capacity that is lacking.
Reise and Muller have 28ah/1000wh bikes that are capable of this, with extra ah comes weight which means a bike at circa 25-30kg or more.
Advancement in lithium battery tech is very slow as there is only so much a small cell can deliver, every few years there is a slight capacity increase with 18650 cells but for now they have reached their zenith at 3500mah, though a lot of very crappy China cells claim a false 5000 -90000 mah.
It is now with 21700 cells that we will see the next developments of capacity for increase in smaller cells though these are fairly expensive especially as the auto industry will be claiming most of these in the push for EV vehicles that will want about 9000 cells per unit. Currently the best 21700 cell deliver 4000/4250mah, Samsung have a 4800 cell but only delivers this at a lowly 0.2a discharge which is no good for ev use.
Last edited by hemo on 24 Jun 2018, 9:43am, edited 2 times in total.

hemo
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Re: Distance on battery

Postby hemo » 24 Jun 2018, 9:33am

Woosh bikes have light weight flat commute bike that can do about 80 miles from 15ah/540wh , this is very dependant on a lot of rider input and low assistance as it is the amp draw that depletes capacity/range. Hills and headwinds are a major factor with range.

bristolroversfc
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Re: Distance on battery

Postby bristolroversfc » 1 Aug 2018, 4:47pm

Hemo....Sorry to but in,but youve mentioned that the battery charging is better if done before each outing(obviously if its been used a little first).
Ive found with my Pulse ZL2,the battery goes down to about 2 green bars after only about 15 miles(at least 2 of these are with no assistance on the flat).
Maybe I should be thinking of charging maybe every other day? Total daily commute is only 4 miles.
Or perhaps let the battery run completly flat,then charge every other day.
Thanks

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Vetus Ossa
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Re: Distance on battery

Postby Vetus Ossa » 2 Aug 2018, 7:02am

Audax67 wrote:A chum who has bored me stiff for weeks talking about eBikes sent me this:

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

He's finally ordered one so I've told him he's riding up front in future unless there's a following wind.


From my experience I would say those figures are pretty spot on.

Eric the Red
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Re: Distance on battery

Postby Eric the Red » 2 Aug 2018, 9:51am

Audax67 wrote:A chum who has bored me stiff for weeks talking about eBikes sent me this:

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

He's finally ordered one so I've told him he's riding up front in future unless there's a following wind.

I also agree with the Bosch calculator. As an example, with a Riese & Muller sport bike; road tyres; 100 kg rider; eco/tour settings; rolling route etc. with a 500w/h battery, I've just done 55 miles at an average of 12.5 mph. Still got 3 bars (out of 5) on the indicator and a possible 40 more mile left from the dashboard predictions. :D

hemo
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Re: Distance on battery

Postby hemo » 2 Aug 2018, 8:14pm

bristolroversfc wrote:Hemo....Sorry to but in,but youve mentioned that the battery charging is better if done before each outing(obviously if its been used a little first).
Ive found with my Pulse ZL2,the battery goes down to about 2 green bars after only about 15 miles(at least 2 of these are with no assistance on the flat).
Maybe I should be thinking of charging maybe every other day? Total daily commute is only 4 miles.
Or perhaps let the battery run completly flat,then charge every other day.
Thanks



Relying on the leds as an idicator of charge state can be misleading, some are fairly accurate and others tend to be way off the mark.
The only real way of determinig battery voltage and possible range is to fit a cheap volt meter or to check the battery voltage with a meter at home, then you will have an idea of voltage left given for each bar that disappears.

I have a KT LCD1 & 2 on two of my bikes that only have a 4 segment battery bar indictor much more reliable then led's and each bar is as near as dammit 25% of range.
My lcd3 is better as it has a continuous voltage level so I know exactly the battery SOC.

stodd
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Re: Distance on battery

Postby stodd » 3 Aug 2018, 10:09am

Just tried https://www.bosch-ebike.com/en/service/range-assistant/ and found it pretty accurate. I thought it was way off (or our battery was) till I noticed its result is in km, not miles. For us around 35 miles from a 13Ah 36V battery on a tandem in a somewhat hilly area on assist levels 2 or 3 (of 5).

I find the 5 level battery indicator on my KT529 (presumably measuring voltage?) a little awkward; except when the battery is really full it tends to drop one bar when there is any significant power from the motor, and drop 2 bars when it is working hard on a hill. I think the middle reading is probably giving the best measure of useful battery. I am surprised the meters don't have amp or power measurement and something to count amps in/out. I have a USB dongle that does that and was just 2 or 3 pounds; it would be a little more for higher voltabge/amps but shouldm't be significant if part of an existing meter.

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fixerupper
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Re: Distance on battery

Postby fixerupper » 3 Aug 2018, 10:38am

I'm in the process of converting one of my bikes to an ebike ...well I'm waiting for the 500/250 watt motor, controller,bottom bracket sensor, brake sensor,36 volt LiON 11 amp hour battery and other stuff to arrive ...so for me this is a interesting thread ...the tech spec for controller that I ordered claims that when down hill freewheeling and braking the battery is in recharge, so extending the range ... is this true ? ...

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cyclemad
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Re: Distance on battery

Postby cyclemad » 3 Aug 2018, 11:53am

my partner and I. have Bosch / ktm e-bikes we use a general commuter / get about bikes when on holiday ( I also take my road bike when I can escape for a couple of hours )

we have done over 50 miles on our e bikes in. day with plenty of battery left so as not to be worried it will run out...including riding on hard sand beaches

I think it all depends on where you ride ( flat / hilly ). the setting you have it on ( we tend to use eco and touring ) and how long you use it ( switch off on flat / downhill )

we love them :)

stodd
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Re: Distance on battery

Postby stodd » 3 Aug 2018, 1:55pm

@fixerupper ebytes don't usually regenerate downhill or on breaking. Most people seem to say that the extra distance gained is small and does not warrant the extra complexity. You don't want to impede normal freewheeling. The tradeoffs might change as time goes on; so it could be true on your kit. Good luck with it.

Technically a motor marked 500/250 will not be road legal even if the controller has a mode that limits it to 250; chances of getting caught are small but could be an issue in case of accident.

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cyclemad
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Re: Distance on battery

Postby cyclemad » 3 Aug 2018, 2:29pm

The BOSCH equipped e-bikes are all road legal ''PEDELECS'' - these are ''electrically ASSISTED '' rather than Electrically powered....and are restricted to 15mph

There are a few BOSCH equipped ''off road'' e bikes but are pretty scarce..

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fixerupper
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Re: Distance on battery

Postby fixerupper » 3 Aug 2018, 2:44pm

Hi stodd .. Yes the wattage question ...The cost was the same for a 250 watt motor or a 250/500 watt motor with PAS..but as .the MTB that I am converting to an E bike is used 90% of the time on the steep and rugged tracks and paths around the remote village in the mountains of Eastern Crete I thought a bit of extra power might be worth having in reserve...Judging by the number of uninsured & untaxed trucks & motorbikes we have here I don't think I need to worry ...

hemo
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Re: Distance on battery

Postby hemo » 3 Aug 2018, 11:27pm

stodd wrote:Just tried https://www.bosch-ebike.com/en/service/range-assistant/ and found it pretty accurate. I thought it was way off (or our battery was) till I noticed its result is in km, not miles. For us around 35 miles from a 13Ah 36V battery on a tandem in a somewhat hilly area on assist levels 2 or 3 (of 5).

I find the 5 level battery indicator on my KT529 (presumably measuring voltage?) a little awkward; except when the battery is really full it tends to drop one bar when there is any significant power from the motor, and drop 2 bars when it is working hard on a hill. I think the middle reading is probably giving the best measure of useful battery. I am surprised the meters don't have amp or power measurement and something to count amps in/out. I have a USB dongle that does that and was just 2 or 3 pounds; it would be a little more for higher voltabge/amps but shouldm't be significant if part of an existing meter.



The reason you see the meter drop a bar or two bars on a hill is voltage sag as a load is applied to the battery this is typical of nearly every battery. When the load is eased the voltage rebounds and settles down again until more load is asked of it. Dependant on how good the cells are spec wise will depend on how much sag there is, this can be anything from 0.3v to 3 or even 4v over the whole battery.
Voltage will yo -yo up and down all the time dependant on the amp load drawn, eventually when the voltage is too low and sag is too much the BMS will come in to play and shut the system down to protect the cells from too deep a discharge and damage. This especially happens on inclines or if a throttle is used a sit demands full load usually.