PoorInRichfield

TL;DR... I'm looking for recommendations for a USB wall charger that can reliably charge the Shimano Di2 BT-DN110-A battery (Ultegra Di2 internal battery) using the SM-BCR2 charger. Bonus points if the wall charger can charge multiple devices at once.

Amazon link or similar is appreciated! By "wall charger", I'm referring to something like this.

The long story if you're super bored...

While I know I could just pick a charger and see if it works, I'd prefer some input from some of you who have "been there, done that" so I don't waste a bunch of time and money buying wall chargers that don't work.

I'm well aware that Shimano recommends charging a Di2 battery using a laptop and requires that the battery charger must be able to provide at least 1 amp of current. I've found that even using a laptop, the laptop has to have a relatively high quality, high current power source or else the Di2 battery still doesn't charge fully. I have two Lenovo ThinkPad laptops and my Di2 battery only charges fully via the higher-end model. If I try to charge the Di2 battery using my less expensive laptop that has the smaller power brick, the light on the Di2 charger goes out about 5 seconds after I plug it into the laptop even though the Di2 battery is only about 30% charged. My guess is that that the power brick just can't deliver enough "juice" to both the laptop and the Di2 charger.

Regardless, having to have my laptop near my bike just isn't convenient as my bike is downstairs on the trainer all winter and my laptop(s) is not. I'd prefer to have a stand-alone USB wall charger that I can keep near my bike to charge not only the Di2 battery, but also my Garmin and various head and tail lights. My pile of bike related electronic components that needs a USB charger seems to keep on growing.

Iride01 

Yeah, I just got Di2 this spring and the Shimano stuff is probably very specific makes sense to someone that has a lot of electrical knowledge and understanding. But not so much to me that is mainly a monkey see monkey do philosophy and just enough electrical knowledge to be dangerous. Shoot, in elementary school I used to amaze others by sticking my foil chewing gum wrappers into outlets with one bare hand and amaze other classmates with the shower of sparks and get scolded by the teachers. I stopped that when I let my hand touch the metal faceplate as I put the foil in one day. But I also learned a little more about grounded circuits since they were rare in older construction back then. Being a new school building, I also became more aware of something called building and electrical codes.

Any how...... I suspect like a cell phone that the SM-BCR2 has circuitry in it to control how much current goes into the battery. But I've not found that in any Shimano literature yet. But apparently any AC adapter with an output of 5 volts and at least 1.0 amps should work. That is one thing Shimano is very specific about. But that draws into question their stating you can charge it on a laptop usb. Many of our old PC's, Mac's and notebooks are only spec'd with .5 amp USB2 ports. USB 3 gives a spec of .9 amps output but I see that there is some talk of a dedicated charging current for USB3 of 1.5 amp. I've got no PC or Mac with USB3 so I'm not exactly sure what is what with dedicated charging ports on a laptop, PC or Mac.

If you read the user manual for the di2 lithium battery, you'll see it says to use a charging current of 1.0 Amps or higher.
https://si.shimano.com/pdfs/um/UM-7FH0A-007-00-ENG.pdf

Adc is Amps DC just in case any are confused. Why they changed convention in the same document is beyond me.

Yet in the same document they say the maximum charge current is 1.0 Amps. So that is why I have to assume the SM-BCR2 controls the charging current. And you just need to connect it to a charger that puts out more than 1.0 Amp with the SM-BCR2 between it and the bike. I use my smartphone turbo-charger.
I've not been without issues charging my Di2. The first time I used a cheapo .5 amp charger that may not even be putting out .5 amps and my battery didn't charge. I didn't know it. So on my ride the next day my front derailleur quit. Just recently, I charged again with my phones AC charger that puts out something like 3.0 Amps. After charging, my Di2 didn't work at all. I hooked it up to e-tube project and everything good. Eventually, it woke up and started working before I got to the point of going to the LBS. So I'm not sure. Maybe it was me and not being on the bike, maybe I wasn't pushing the levers fully or something. But that will have to wait for the next charge in a few more months to find out.

jadocs

Apple wall socket has been working just fine for me. I have found that no name (brands) have to be tested. If the light goes off after 15-30 min, it's generally a sign that it is not rated to the required Amps.

PoorInRichfield

Unfortunately, my phone's charger has a USB 3.0 plug on it and obviously can only charge a single device even if it didn't.

I'm thinking the following will be my next Amazon purchase as it claims 5V / 2.4 A which should theoretically be good enough for the Di2 battery and the host of other electronic bike components that also require USB charging. If it doesn't work, I'll use Amazon's free return process.

HITRENDS Surge Protector with 6 AC Outlets & 6 USB Charging Ports

Tourist in MSN

I do not have a Di2 system, so this is perhaps a stupid question. If you need at least a 1 amp charging rate on a standard USB port, could you just plug it into a good quality powerbank. And then recharge the powerbank at your leisure?

If the battery is 3.7 watt hours, that is not a lot of capacity. It should be easy to find a powerbank that is large enough to charge it several times that has an adequate charging rate.

Iride01 

Doesn't matter if the port on your phone charger is USB 3 or not. Although I can't imagine why it would be USB 3 type A. It's probably just a type A USB and your cable that came with it a USB 3 type A. The pins for charging are only the outer pin on each side. Everything else is all about data, which you don't use while charging. So the actual pins that carry power to the charger match up with new or old cables that have a type A connector whether made for USB version 1, version 2 or 3 and possibly future versions..

AFAIK, all the stuff to control charging rates on a modern smartphone are in the phone itself. The charger just converts and preconditions the voltage and current. Likewise, that is why the SM-BCR2 must (again AFAIK) be between the AC adapter and the bikes battery. As it actually controls the charge rate, just in case your AC adapter puts out an obscene amount of amperage.

That will be a nice power supply. I just don't have six Di2 bikes needing charging all at the same time.

PoorInRichfield

We all could only wish we had 6 Di2 equipped bikes to charge at the same time! In addition to charging my bike, I also need USB charging capabilities for my Garmin 830, front and rear Bontrager Flare RT lights, and NiteRider headlight... and who knows what'll need to charge in the future. It's only the Di2 battery that seems to be really finicky about the charger, but I'd like to be able to plug all that stuff in at once if need-be rather than one at a time like I do now.

PoorInRichfield

I'll have to give that a try... the wifey has a power bank she isn't using. I'll report back next time my Di2 needs charging...

Iride01 

At the risk of answering questions well above my paygrade, I'd say the answer is yes you can.

Electricity is electricity whether it comes from a battery source or a power plant. You just need to make sure that what is being fed to the SM-BCR2 is 5.0 volts DC and at least 1.0 Amps.

Thing is, Di2 and other's don't need charging but a few times a year. The battery in the handlebar is 500 mAh capacity. Don't know what the other Di2 batteries are. But a battery bank that can supply the current should work well if you get caught out. But are you going to also have the SM-BCR2 with you? If not you might risk damaging the battery.

PoorInRichfield

I don't see a way around the SM-BCR2 due to the proprietary connector on the bike's charge port, so yes... that'll be in the chain-o-power-cords

I agree that Di2 shouldn't need charging very often, but for some reason my Di2 was completely dead last night when just a day or two before it was at 50% charge. So either my battery is on it's way out or the cold temps in my basement caused the battery to drain faster than normal... although I wouldn't think temps in the mid-50F would do that.

NoWhammies

Years ago, when I ordered my very first Garmin watch (a 405 if you're curious) the watch came with a wall charger. A big sucker. Not like the small little cubes that come with iPhones. Anyway. The wall charger puts out enough power to charge the Di2 system so that's what I use. Perhaps you can find an old Garmin charger lying around and make use of that.

Cyclist0108

Check for loose connections. I also agree it shouldn't do that. (Mine hasn't since 2014 when I got it.) I charge with an iPad charger. I've not had good luck charging with cheap USB wall-warts. A USB C charger and adaptor should also work.

August West

You didn't by chance connect to the bike with the new E-tube v4.0.2 PC app before the battery drained did you?

PoorInRichfield

I did... what do you know!?!?!? Spill the beans!!!

PoorInRichfield

The power bank does indeed work. Thanks to Tourist in MSN for the suggestion! Granted, this solution requires charging the power bank only to charge the Di2 battery hence introducing a "middle man", but it does give me an option for charging my Di2 battery w/o having to have my laptop nearby which is important to me.

Now if there was only a way to bypass the Shimano SM-BCR2, one could just carry a power bank on a ride as a back-up for one's phone and Di2. I got stuck in a single gear this Summer when I got notified about 15 minutes into my ride that my Di2 battery was low. I figured it'd last until the end of my 40 mile ride, but I was wrong.

Tourist in MSN

You are welcome. Glad it worked.

I think there is no way to bypass the Shimano charger unit, one of the links above indicated that the Shimano battery pack is 7.4 volts, that would be double the voltage for generic off the shelf Li Ion battery chargers.

I have a generic Li Ion charger (Pixo C-USB) that can sense if a battery is 3.7 or 7.4 volts, but it is no longer sold. I bought it as some of my DSLR cameras take a 7.4v battery pack.

August West

There is a bug with the new version. Long story short, I would use the old v3.x version until Shimano fixes the v4.x version. The install of 4.0.2 leaves the old version alone so you should still have it on your PC or it can still be downloaded.

I had this issue and I've confirmed it with Terry who runs the Bettershifting.com site.

Long version. My battery was down to 50% so I decided to charge it up (from a wall wart) since I never let it get below 40-50%. After charging it I decided to plug in the laptop and check out the new v4 version of the E-tube software I had downloaded. I looked around for a bit but didn't change anything. Made sure and hit the "Disconnect" button before exiting. I was unable to ride for the next 2 days. On the 3rd day I went to go for ride and the Di2 was totally dead. Never happened before and the bike is only 8 months old. Charged it up a bit and everything returned to normal. Went for my ride and finished charging it when I got back home. Over the next few days everything was back to normal with no drain.

I got to wondering what happened so I took the laptop back out and connected with v3.x. Everything was fine. Then I connected v4.0.2. Everything appeared fine. Made 100% sure I hit the "Disconnect" button. Unplugged the cable and checked the bike. Totally unresponsive again. I knew it couldn't drained the battery from 90% charge in the few seconds I had it hooked up but tried charging it up to see if it would fix it. No dice after 20 minutes of charging. Call my LBS and they hadn't heard of this but told me to bring it in so they could look at with their diagnostic module. Before doing that I decided to try connecting with v3.x again. Connected then immediately disconnected with v3.x and the Di2 was back to normal with 90% battery charge.

At this point I emailed Terry to see if he had heard of this. It turns out he had the same thing happen and there are other issues with trying to make adjustments via the v4.0.2 software.

Per his suggestion I connected with v4.0.2, disconnected immediately, reconnected again and then disconnected. After this double connection sequence the bike was fine. It turns out there is something funky going on when you connect for the first time with v4.0.2. For whatever reason, if you disconnect and reconnect it connects properly the second time. A tell-tale sign is when you connect there should be a battery icon next to the "Disconnect" button on the upper left part of the screen. The battery icon does not show up on the first connection, but on the second it shows up and displays the battery level properly.

When you disconnect after the first connection it leaves this system in the wrong state (like when you are connected) which leaves it unresponsive and will drain the battery quickly.

Maybe Terry will chime in and add to this.

GAtkins

So you're saying that v4.0.2 then works fine every future time or do you have to connect and disconnect it twice every time you use it? Thanks.

Glenn

PoorInRichfield

Sounds like the situation I ran into for sure. My bike is a 2020 model, so I was concerned that somehow my relatively new Di2 battery was now kaput and going to cost me $150 to fix. I'm not sure if I uninstalled the old e-Tube, but I don't see it anymore in "Add/Remove Programs". I don't really need to use it for anything and I have the mobile app as well, so I think I'll just be sure to use the mobile app for now until I see a new desktop e-Tube update.

I also learned that if one shifts the bike while it's not in-motion, like while one's bike is on a trainer (which mine is), there's the potentially that Di2 will try to shift but can't and thus drain the battery. For example, if one isn't pedaling but clicks the left lever to downshift the front derailleur and leaves the bike that way for a few days, Di2 thinks to itself, "This guy wants a down shift... Dang, it's sure hard to move the chain off the big ring for some reason, I'll keep trying until I die."

Steve B.

I read this and can only think "WTF is Shimano thinking ?". They have had E-Tube software issues since the beginning, if I didn't know better I say they are sourcing out their OS development to Garmin. Reading this and having seen in the past, issues with trying to update using the mobile app and bricking the system when the WU-111 unit gets updated, makes me never plug in my system to E-Tube as it otherwise works perfectly.

August West

I think it is every time you use it but I haven't really tested it. Once I got things back to working I've left it alone. If I need to do anything I always use the smart phone version. The only reason I checked out PC app was curiosity.

GAtkins

Thank you.

Glenn

August West

The older version is still available for download on the E-tube website should anybody need it.

jadocs

Interesting, I have connected a couple times with v. 4.0.2 on my phone and have not suffered any ill effects. The last time was about a month ago. I would think the battery would have drained by now if the connection was still active? I'll check the battery level tonight when I get home and see what percent it is at.

I always swipe up and close the app on my phone if that makes a difference. I don't let anything run in the background.

Steve B.

The issues August is reporting with 4.02 is on a wired connection to the software on a PC, not the BT connected version.