On 30/01/2020 00:36, Tom Kunich wrote:
On Wednesday, January 29, 2020 at 1:07:02 PM UTC-8, jbeattie wrote:
On Wednesday, January 29, 2020 at 12:26:32 PM UTC-8, Tom Kunich
wrote:
On Wednesday, January 29, 2020 at 12:00:57 PM UTC-8, jbeattie
wrote:
On Wednesday, January 29, 2020 at 11:17:16 AM UTC-8, Tom Kunich
wrote:
On Tuesday, January 28, 2020 at 5:36:21 PM UTC-8, jbeattie
wrote:
On Tuesday, January 28, 2020 at 4:59:05 PM UTC-8, Tom
Kunich wrote:
On Tuesday, January 28, 2020 at 1:40:42 AM UTC-8,
wrote:
On Monday, January 27, 2020 at 1:59:08 AM UTC+1, Tom
Kunich wrote:
On Thursday, January 9, 2020 at 9:43:42 AM UTC-8, Tom
Kunich wrote:
It occurs to me that I should install the hydraulic
brakes before I attach the electronic wiring. What
do you think?

Well, I have put the Di2 together. And nothing works.
The possible sources of error a

1. The wiring is incorrect. I assumed that the left
and right shifters would go into the left and right
connector of to two holes of the 5 hole Stem unit.
The manual is not clear about this so it was ad lib.

2. The new battery could be flat. I have no way of
measuring the voltage under load but the unloaded
voltage is 8 volts and Shimano says that 7 something
volts is a full charge. I bought a new charger but I
don't think it was new since it didn't come in a box
or sealed plastic bag and when I questioned the
seller he promptly returned my money and said that I
could keep the charger. Looking at the output voltage
it measures zero but I don't know what the charging
circuitry is. It could turn off with no detectable
load. Hmmm. So I bought another "new" charger and
hopefully this one will work.

So the question is this: Could the battery be so flat
that the unit wouldn't turn on?

Possible, but I never came across a new battery out of
the box that was so dead that it wasn't able to power a
led.

Lou

I find it curious as well. Nut Lithium Ion batteries are
odd works. Perhaps plugging it into the battery charger
whish isn't working drained the battery. And the high
voltage measurement I got was because there was no load
on it.

In any case the new charger should arrive Friday and I'll
test the charge again.

Otherwise I'll have to replace the stem unit. I have no
idea why his stem junction box is a five port unless he
was running TT bars with end shifters.

Is this a trick question? If your battery is showing 8v,
it's not dead. No? Why would load matter -- except for
measuring capacity. I understand the battery may have a
protection circuit, but wouldn't that decrease the measured
voltage?

I don't have an EE degree, but I measure batteries with a
multimeter all the time to see if they are alive or dead,
and if one showed 8v it would not be dead. I think you
messed something up. Just check the quality of your
connections. Do you have the little tool?
https://www.youtube.com/watch?v=OkdY9q-u5Dk If you're not
fishing wires, it's really pretty fast and easy. Its the
fishing that takes time.

-- Jay Beattie.

Jay, stop showing that you don't know anything about
engineering. A battery is similar to a capacitor to the
extend that load matters to output voltage. Even a small
charge on a battery can show "normal" voltage if you are
measuring it unloaded.

So what is the likelihood that a battery showing 8v will not
produce enough current to run a tiny LED? I mean your not
cranking a starter motor. I represent these guys and will see
what they have to say. https://mobilepowersolutions.com/
Every time you have some problem, it turns out to be some
bizarre mistake, as with your bottom bracket measurement, seat
tube clamp diameter, etc., etc. This is not rocket science. Di2
is an easy install.

-- Jay Beattie.

Tell us how many Di2 you personally installed? What is bizarre is
that you represent some people and hence know electronics
engineering. Or that you believe that the only thing inside that
stem junction box is an LED.

Exactly one. And I confess to breaking the wire to my RD while
washing the bike a little too vigorously on my wash stand (dragged
the wire into the cassette with a brush). I soldered it back
together and used some shrink tube to seal it up. I may put in a
replacement wire one day. That shorted the battery, BTW, which has
had no problems since. I also confess to needing to read up on
programming because I want to change some presets.

You don't need an EE to build a Di2 bike. All you need is YouTube.
And I'm sure there is more than an LED in the junction box, but it
it is getting power, the LED will blink red at basically any
voltage output until it is absolutely dead. I would figure that you
would get the blinking red with even a bad battery with some
voltage output if it were properly wired. Check all your
connections again. Use the tool.

-- Jay Beattie.

Jay, an LED requires 1.5 volts bias or so to turn on. This is why I
was saying to you to not try to be an EE. You can easily discharge
the battery to below the bias simply by leaving everything on. At
$100 for a battery I sure hope this bad battery charger didn't ruin
the battery.

I'm pretty sure the Di2 contains a couple of 14430s, at about 10USB.
I'd have also thought an LED would start conducting around the 0.7V
mark. Ok, not very bright. Btw, I'm not an EE either.