Di2 battery not included?

Op 22-8-2012 20:23, Jay Beattie schreef:
On Aug 22, 10:14 am, Lou Holtman wrote:
Op 22-8-2012 1:34, James schreef:









A quick internet search shows the Di2 battery is 7.4 V, 530 mAh which
supposedly lasts 1600 km depending on temperature and shift frequency.

http://artisancycles.com.au/article-custom-di2-battery-for-cyfac-absolu/

Assuming 30 km/h average speed, 1600 km is equivalent to 53 h of riding.

Di2 average current and power consumption:

530 mAh / 53 h = 10 mA.

10 mA x 7.4 V = 74 mW.

I hate charging batteries, as I've noted before. So what would make
this work without batteries? My guess is a linear generator and super cap.

Linear generator for a bicycle has been done.

http://www.slideserve.com/andralyn/energy-harvesting-bicycle-light

And they could generate enough power with this (a little crude, hacked
together assy) to power Di2, 95 - 150 mW.

Is there hope for a battery free Di2 yet?

I would go through all that trouble to avoid charging a battery once
every 2-4 weeks?

Wow, are you training for something? I haven't done 500 miles in a
week except on tour.

-- Jay Beattie.



1600 km not miles. I do 300-400 km a week in peak season. A friend even
more. I know people who ride 25000 km a year. I manage half of that.
They would have to charge that battery 15 times a year if the use just
one bike. If he forgets to charge the battery he has to postpone his
ride for one hour. Something would happen to a friend of Frank all the
time ;-). Big deal.

Lou

On 23/08/12 03:14, Lou Holtman wrote:
Op 22-8-2012 1:34, James schreef:
A quick internet search shows the Di2 battery is 7.4 V, 530 mAh which
supposedly lasts 1600 km depending on temperature and shift frequency.

http://artisancycles.com.au/article-custom-di2-battery-for-cyfac-absolu/


Assuming 30 km/h average speed, 1600 km is equivalent to 53 h of
riding.

Di2 average current and power consumption:

530 mAh / 53 h = 10 mA.

10 mA x 7.4 V = 74 mW.

I hate charging batteries, as I've noted before. So what would make
this work without batteries? My guess is a linear generator and super
cap.

Linear generator for a bicycle has been done.

http://www.slideserve.com/andralyn/energy-harvesting-bicycle-light

And they could generate enough power with this (a little crude, hacked
together assy) to power Di2, 95 - 150 mW.

Is there hope for a battery free Di2 yet?



I would go through all that trouble to avoid charging a battery once
every 2-4 weeks?


If the generator was part of the system, you would install and forget
(until the bushes in the derailleur wore out ;-), and you'd not be
caught half way through a mountainous 200km event with a flat battery -
bonus!

--
JS.

On 23/08/12 04:00, SMS wrote:
On 8/21/2012 4:34 PM, James wrote:

Is there hope for a battery free Di2 yet?

It would be quite easy. A hub dynamo, rectifier, and some super caps. It
would not be cheap.

And comparatively heavy and an unwanted drag, and long wiring runs. No,
the idea of a linear generator that has the added benefit of absorbing
some vertical motion energy is far better.

You can buy some LiPo batteries and a charger for around $50.

Um, the idea is to ditch the batteries...

--
JS

On 23/08/12 04:57, Lou Holtman wrote:

The battery is NOT a problem with Di2 or Campy EPS when used were it
meant for. Don't make one up especially the people who never used the
system and/or would never buy one in the first place.

I use a Garmin Edge 305 bike computer. I hate it that I have to charge
it after every 6 hours of riding, but I enjoy checking out the course
profile my heart rate stats, etc., and competing on strava for that matter.

One day I'll probably end up with electronic gear shift on a bike. Is
there something wrong with trying to make it better?

Batteries are not good things in my opinion, and if they can be
effectively replaced by something better, I'm all for it.

--
JS.

On 23/08/12 04:55, wrote:
Apparently the person writing this post should have done some more
internet searching. The Di2 batteries last about 1600 MILES. Not
1600 kilometers. So if the Di2 bike is your only bike, not likely,
and you are riding a lot, you can easily go 4-6 weeks before
recharging. Does not seem like much of a burden to me. My Di2 bike
is one of the fleet. So its only ridden once a week or so. It might
get the battery charged once or twice a year. And when the battery
gets weak, the front derailleur stops working first. The rear
derailleur continues to shift for hundreds of more miles. Easy to
figure out you need to charge the battery. The only people concerned
about the battery running out are the ones who have never ridden with
Di2. The ignorant.

[Please don't top post. Reply inline as per RFC1855]

I see other references of 1000 mi, or 1600 km.

http://www.racycles.com/products/detail/28424

But then;

http://www.bicycling.com/gearfinderp...ail?gfid=12049

"Battery life: 621 miles per charge (claimed) but testing shows a life
of about 1,600 miles, according to Shimano"

A very broad range, yet so precise with the 621 miles. Curious.

Well, if the battery lasts 1600 miles, it makes the idea of using a
linear generator even more plausible!

I only have one road bike. I train and race on it. IF the battery
lasted 1000 mi (1600 km), I'd need to charge every 6 weeks. And because
I don't like being caught in the hills with a flat battery, I'd rather
err on the side of caution and charge the battery more frequently. I
deem this a pain in the arse. Others obviously have the same opinion,
otherwise the site I first linked to
http://artisancycles.com.au/article-custom-di2-battery-for-cyfac-absolu/
wouldn't need to advertise batteries with higher capacity to increase
the recharge period.

Then there's the problem of battery degradation. After X recharge
cycles, battery capacity is generally reduced and the system stops
working properly when you least expect it (or need it).

And for what it's worth, having the front derailleur stop working would
be a pain in the arse that I don't get from my stainless steel cable
operated gears.

I have enough experience of needing to charge batteries to know my
opinion on the subject.

How compelling was your case? Not at all. Keep trying.

--
JS.

On 23/08/12 09:02, Phil W Lee wrote:
considered Wed, 22 Aug 2012 10:14:30 -0700
(PDT) the perfect time to write:

On Aug 22, 10:30 am, Phil W wrote:
considered Wed, 22 Aug 2012 06:06:25 -0700
(PDT) the perfect time to write:





On Aug 21, 7:34 pm, wrote:
A quick internet search shows the Di2 battery is 7.4 V, 530 mAh which
supposedly lasts 1600 km depending on temperature and shift frequency.

http://artisancycles.com.au/article-custom-di2-battery-for-cyfac-absolu/

Assuming 30 km/h average speed, 1600 km is equivalent to 53 h of riding.

Di2 average current and power consumption:

530 mAh / 53 h = 10 mA.

10 mA x 7.4 V = 74 mW.

I hate charging batteries, as I've noted before. So what would make
this work without batteries? My guess is a linear generator and super cap.

Linear generator for a bicycle has been done.

http://www.slideserve.com/andralyn/energy-harvesting-bicycle-light

And they could generate enough power with this (a little crude, hacked
together assy) to power Di2, 95 - 150 mW.

Is there hope for a battery free Di2 yet?

--
JS.

rechargeables suck; it would ve been... ten times, nay, hundred times
more practical if they incorporated AA standard type.

six AAA 1.2v NiMH low self-discharge cells would keep to standard
battery formats and give almost the same voltage, but around 800mAh.
But then you wouldn't be forced to buy replacements at a wildly
inflated price from Mr Shimano, or be forced to upgrade when Mr
Shimano decides to stop selling them.
Throw in a dummy cell so that users could fit alkalines in an
emergency.- Hide quoted text -

- Show quoted text -

ahhh, thanks I was wondering what kind of equivalent power it would
be- I reckon its about the same drain as my polar g3 gps ( 1 duracell
aa lasts about 6 hours continous use)- thats a pretty high drain imho

Well, to put it another way, if you tapped into a typical bicycle
generator system (~6v 0.5A) you'd not notice the difference - the
battery could be charged from the surplus in the lighting system when
it's not needed or you're going fast enough to have some spare.
10mA is only 2% of the 0,5A available from a lighting generator.
A generator designed for the purpose and built into (say) the rear hub
would give so little drag you'd need very sensitive instrumentation to
even detect it.

That's what I like about the linear generator idea. Ok, if you're
already running a hub dyanmo, make use of the hardware, but to replace
the Di2 battery with something that absorbs a little power from vertical
motion might even smooth your ride a little without absorbing any
horizontal motion power!

--
JS.

On Aug 22, 3:36*pm, James wrote:
On 23/08/12 04:55, wrote:

Apparently the person writing this post should have done some more
internet searching. *The Di2 batteries last about 1600 MILES. *Not
1600 kilometers. *So if the Di2 bike is your only bike, not likely,
and you are riding a lot, you can easily go 4-6 weeks before
recharging. *Does not seem like much of a burden to me. *My Di2 bike
is one of the fleet. *So its only ridden once a week or so. *It might
get the battery charged once or twice a year. *And when the battery
gets weak, the front derailleur stops working first. *The rear
derailleur continues to shift for hundreds of more miles. *Easy to
figure out you need to charge the battery. *The only people concerned
about the battery running out are the ones who have never ridden with
Di2. *The ignorant.

[Please don't top post. *Reply inline as per RFC1855]

I see other references of 1000 mi, or 1600 km.

http://www.racycles.com/products/detail/28424

But then;

http://www.bicycling.com/gearfinderp...ail?gfid=12049

"Battery life: 621 miles per charge (claimed) but testing shows a life
of about 1,600 miles, according to Shimano"

A very broad range, yet so precise with the 621 miles. *Curious.

Well, if the battery lasts 1600 miles, it makes the idea of using a
linear generator even more plausible!

I only have one road bike. *I train and race on it. *IF the battery
lasted 1000 mi (1600 km), I'd need to charge every 6 weeks. *And because
I don't like being caught in the hills with a flat battery, I'd rather
err on the side of caution and charge the battery more frequently. *I
deem this a pain in the arse. *Others obviously have the same opinion,
otherwise the site I first linked to
http://artisancycles.com.au/article-custom-di2-battery-for-cyfac-absolu/
wouldn't need to advertise batteries with higher capacity to increase
the recharge period.

Then there's the problem of battery degradation. *After X recharge
cycles, battery capacity is generally reduced and the system stops
working properly when you least expect it (or need it).

And for what it's worth, having the front derailleur stop working would
be a pain in the arse that I don't get from my stainless steel cable
operated gears.

I have enough experience of needing to charge batteries to know my
opinion on the subject.

How compelling was your case? *Not at all. *Keep trying.

I hear the shifting is incredible -- but you have to commit to the
system: recharging, replacing, paying, etc., etc. I'm too lazy and
too broke for all that -- plus I'm a Luddite. I'm sure it will become
the dominant system in five years or sooner -- and I will get trickled
down upon. It's just a matter of time -- like flat screen TVs.

-- Jay Beattie.

James wrote:
On 23/08/12 03:14, Lou Holtman wrote:
Op 22-8-2012 1:34, James schreef:
A quick internet search shows the Di2 battery is 7.4 V, 530 mAh which
supposedly lasts 1600 km depending on temperature and shift frequency.

http://artisancycles.com.au/article-custom-di2-battery-for-cyfac-absolu/



Assuming 30 km/h average speed, 1600 km is equivalent to 53 h of
riding.

Di2 average current and power consumption:

530 mAh / 53 h = 10 mA.

10 mA x 7.4 V = 74 mW.

I hate charging batteries, as I've noted before. So what would make
this work without batteries? My guess is a linear generator and super
cap.

Linear generator for a bicycle has been done.

http://www.slideserve.com/andralyn/energy-harvesting-bicycle-light

And they could generate enough power with this (a little crude, hacked
together assy) to power Di2, 95 - 150 mW.

Is there hope for a battery free Di2 yet?



I would go through all that trouble to avoid charging a battery once
every 2-4 weeks?


If the generator was part of the system, you would install and forget
(until the bushes in the derailleur wore out ;-), and you'd not be
caught half way through a mountainous 200km event with a flat battery -
bonus!

For such a small amount of power, I wonder if a spoke-mounted magnet
passing a chainstay-mounted coil, plus a bit of rectification, etc.
would do the trick.


--
- Frank Krygowski

On Wed, 22 Aug 2012 19:14:11 +0200, Lou Holtman
wrote:

Op 22-8-2012 1:34, James schreef:
A quick internet search shows the Di2 battery is 7.4 V, 530 mAh which
supposedly lasts 1600 km depending on temperature and shift frequency.

http://artisancycles.com.au/article-custom-di2-battery-for-cyfac-absolu/

Assuming 30 km/h average speed, 1600 km is equivalent to 53 h of riding.

Di2 average current and power consumption:

530 mAh / 53 h = 10 mA.

10 mA x 7.4 V = 74 mW.

I hate charging batteries, as I've noted before. So what would make
this work without batteries? My guess is a linear generator and super cap.

Linear generator for a bicycle has been done.

http://www.slideserve.com/andralyn/energy-harvesting-bicycle-light

And they could generate enough power with this (a little crude, hacked
together assy) to power Di2, 95 - 150 mW.

Is there hope for a battery free Di2 yet?



I would go through all that trouble to avoid charging a battery once
every 2-4 weeks?

Lou

Or you could buy the Shimano made, guaranteed never to require
re-charging, system :-)

On 23/08/12 11:02, Frank Krygowski wrote:
James wrote:
On 23/08/12 03:14, Lou Holtman wrote:
Op 22-8-2012 1:34, James schreef:
A quick internet search shows the Di2 battery is 7.4 V, 530 mAh which
supposedly lasts 1600 km depending on temperature and shift frequency.

http://artisancycles.com.au/article-custom-di2-battery-for-cyfac-absolu/




Assuming 30 km/h average speed, 1600 km is equivalent to 53 h of
riding.

Di2 average current and power consumption:

530 mAh / 53 h = 10 mA.

10 mA x 7.4 V = 74 mW.

I hate charging batteries, as I've noted before. So what would make
this work without batteries? My guess is a linear generator and super
cap.

Linear generator for a bicycle has been done.

http://www.slideserve.com/andralyn/energy-harvesting-bicycle-light

And they could generate enough power with this (a little crude, hacked
together assy) to power Di2, 95 - 150 mW.

Is there hope for a battery free Di2 yet?



I would go through all that trouble to avoid charging a battery once
every 2-4 weeks?


If the generator was part of the system, you would install and forget
(until the bushes in the derailleur wore out ;-), and you'd not be
caught half way through a mountainous 200km event with a flat battery -
bonus!

For such a small amount of power, I wonder if a spoke-mounted magnet
passing a chainstay-mounted coil, plus a bit of rectification, etc.
would do the trick.



Hmm. Dunno 'bout that. It has down sides, like if you have different
wheels you need magnets on all and positioned correctly. For that
reason I can't see it working for Le Tour. Also different spoke designs
are not always conducive to fixing a magnet.

I see a linear generator as "Active Damping" (tm) for your frame ;-)

--
JS.