Charging di2 batteries with dc power source

Is it possible to charge an internal Di2 battery using a etube spliced to a dc battery charger with the correct dc voltage. Like to have a charged internal battery in the toolbox when I need it.

On 10/2/2018 9:06 PM, ixiz wrote:
Is it possible to charge an internal Di2 battery using a etube spliced to a dc battery charger with the correct dc voltage. Like to have a charged internal battery in the toolbox when I need it.

If the battery is just a standard 2S Li-Ion pack (3.7V x 2) then using
an 8.4V/1A Li-Ion charger, like what is used for many lights, would work.

Over 8.4V and you could have a nice explosion, though the battery pack
probably has its own over-voltage protection circuit.

Probably not a good idea to use a variable DC supply.

I’m not certain hence the question. I do know there are electronics in the battery that uses canbus for communication to other components

On 10/3/2018 4:51 AM, ixiz wrote:
I’m not certain hence the question. I do know there are electronics in the battery that uses canbus for communication to other components

The CANBUS data is modulated on the power lines, but I doubt if the
battery has a CANBUS controller inside it.

On Wednesday, October 3, 2018 at 10:05:45 AM UTC-4, sms wrote:
On 10/3/2018 4:51 AM, ixiz wrote:
I’m not certain hence the question. I do know there are electronics in the battery that uses canbus for communication to other components

The CANBUS data is modulated on the power lines, but I doubt if the
battery has a CANBUS controller inside it.

I dont know much bout electronics - hence the confirmation before i damage anything

I just want to be able to have a charged internal di2 battery when i need it as a loaner or help someone that needs it when as needed - I dont have the new 6880 nor the 8050 system - i have a 6770 (10s) external battery

On Wednesday, October 3, 2018 at 9:10:35 AM UTC-5, ixiz wrote:
On Wednesday, October 3, 2018 at 10:05:45 AM UTC-4, sms wrote:
On 10/3/2018 4:51 AM, ixiz wrote:
I’m not certain hence the question. I do know there are electronics in the battery that uses canbus for communication to other components

The CANBUS data is modulated on the power lines, but I doubt if the
battery has a CANBUS controller inside it.

I dont know much bout electronics - hence the confirmation before i damage anything

I just want to be able to have a charged internal di2 battery when i need it as a loaner or help someone that needs it when as needed - I dont have the new 6880 nor the 8050 system - i have a 6770 (10s) external battery

I really don't think its worth your trouble to even investigate this topic. My 7970 Di2 battery lasts 2-3 YEARS before needing recharge. And when a recharge is necessary, it turns off the front derailleur shifting first, you can still use the rear shifter for many, many miles. Eventually both derailleurs would stop working I suppose. Having a dead Di2 battery is about as common as having a lunar and solar eclipse in a month with two full moons. And Christmas, New Years and Thanksgiving all falling in the same month too.

On Tue, 2 Oct 2018 21:06:13 -0700 (PDT), ixiz
wrote:

Is it possible to charge an internal Di2 battery using a etube spliced
to a dc battery charger with the correct dc voltage. Like to have a
charged internal battery in the toolbox when I need it.

Perhaps it would be better to check the battery charge level before
charging? To the best of my limited knowledge, most systems have this
featu
"Check Di2 Battery Status (Updated)"
https://www.youtube.com/watch?v=8yJxaNRLXi8
To check the battery status, simultaneously hold down the
two right hand shifter buttons for a couple of seconds
and the top LED under the battery symbol will illuminate.
A solid green light indicates a full charge. A flashing
green light indicates roughly 50%, a solid red light
indicates roughly 25% and a flashing red light means the
battery is pretty much empty.

I'm not sure what an "etube spliced to a DC battery charger" might be,
but I suspect it's NOT the correct way to charge a LiIon battery. The
Di2 looks like 7.4V at 500 ma-hrs. I use an RC model airplane charger
for most everything:
https://hobbyking.com/en_us/imax-b6-50w-5a-charger-discharger-1-6-cells-genuine.html
I hesitate to recommend one of the smaller and cheaper chargers that
cannot be programmed for the specific battery configuration.




--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 10/7/2018 10:06 AM, Jeff Liebermann wrote:

snip

t 500 ma-hrs. I use an RC model airplane charger
for most everything:
https://hobbyking.com/en_us/imax-b6-50w-5a-charger-discharger-1-6-cells-genuine.html
I hesitate to recommend one of the smaller and cheaper chargers that
cannot be programmed for the specific battery configuration.

The "smaller and cheaper chargers" come in 1S (4.2V) and 2S (8.4V) models.

I have one of the balance chargers like yours. It can charge each cell
in a series pack individually, which can be done much faster than
charging a series pack in series with a higher voltage, and it avoids
unbalanced cells.

For a 2S battery, there's no downside in charging it with an 8.4V
charger provided you can get to the charging contacts on the battery
pack and there is no damage to the CANBUS circuitry which modulates
communications onto the power lines.

On Sunday, October 7, 2018 at 1:06:49 PM UTC-4, Jeff Liebermann wrote:
On Tue, 2 Oct 2018 21:06:13 -0700 (PDT), ixiz
wrote:

Is it possible to charge an internal Di2 battery using a etube spliced
to a dc battery charger with the correct dc voltage. Like to have a
charged internal battery in the toolbox when I need it.

Perhaps it would be better to check the battery charge level before
charging? To the best of my limited knowledge, most systems have this
featu
"Check Di2 Battery Status (Updated)"
https://www.youtube.com/watch?v=8yJxaNRLXi8
To check the battery status, simultaneously hold down the
two right hand shifter buttons for a couple of seconds
and the top LED under the battery symbol will illuminate.
A solid green light indicates a full charge. A flashing
green light indicates roughly 50%, a solid red light
indicates roughly 25% and a flashing red light means the
battery is pretty much empty.

I'm not sure what an "etube spliced to a DC battery charger" might be,
but I suspect it's NOT the correct way to charge a LiIon battery. The
Di2 looks like 7.4V at 500 ma-hrs. I use an RC model airplane charger
for most everything:
https://hobbyking.com/en_us/imax-b6-50w-5a-charger-discharger-1-6-cells-genuine.html
I hesitate to recommend one of the smaller and cheaper chargers that
cannot be programmed for the specific battery configuration.




--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff,
How do you connect your RC model airplane charger to the Di2 internal battery ?

On Mon, 8 Oct 2018 12:54:06 -0700 (PDT), ixiz
wrote:

Jeff,
How do you connect your RC model airplane charger to the Di2 internal battery ?

I don't have a Di2 or an electric shifting system. Worse, I can't
tell from photos on the web exactly how the battery connector works.

I suggest you find a EW-SD50 extension cable, which I think will fit
the STM-BTR2 LiIon battery (not sure), cut it in half, and you have
two battery charging cables. Please double check if the EW-SD50
extension will fit the STM-BTR2 battery before blundering forward:
https://www.google.com/search?q=Shimano+EW-SD50&tbm=isch
Strip back the cable jacket and the insulation from the wires, attach
the clip leads that come with the RC charger to the wires, and you
should be able to charge the battery. It would be nice if the Di2
battery had a JST-XH balance charger connector so that the charger can
deal with unbalanced cells. However, with the low current usage of
the electric shifting system, I doubt that it will ever be a problem
unless you abuse the battery in some manner.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558