[AbsoluteZero]

Any group member, that's removed the DCM (telemetric module) under the radio, have info on it's backup battery. A web search shows the p/n 57433SG000. Price $50+. Is it a common battery, for example, with leads attached. Voltage?? power?? A web search has not found any details for the battery's specs.

 

[brucep]

Judging from the photos, it sure looks like a 18650 rechargeable lithium Battery.... with pigtail soldered to it. Literally every rechargeable device on the planet uses 18650 batteries. (even many EVs)

https://e-radionica.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/d/s/dsc_5548.jpg

Keep in mind that there are not a lot of battery-sizes in the world.... perhaps you could measure the one you have to help identify what it is.

I assume you realize it is nearly trivial to solder a couple wires to a battery by moving pigtail from old battery. (beware of battery-safety regarding heat!!)

 

[AbsoluteZero]

That would be my guess too.... although a 18500 (slightly smaller) could be the size. I have used both in repowering small flashlights. I don't have the old one out yet but doesn't look too difficult removing the radio to get at it.

 

[walker]

Lithium Ion
3.2volt
1100 mAh
made in china.

don't know anything beyond that. This is from some subaru document on the 2016 model year changes. part number is different. Can't find any references to the part number except in several subaru documents... figures.

Subaru says the service life of that battery is 5 years, but to only replace it when you get DTCs. I imagine there will be more and more cars needing these soon... the 2016 cars are at 6 years now. Anything you figure out should help others

pics from the training material. Doesn't mean this is the part number that is actually in your outback, but it might be.

 

[Fibber2]

Ouch.... We had the DCM die on the 2018 Forester last year and SOA covered it including the deductable under the Gold plan (about $700 plus labor). But the dealer pushed me on the battery (car was built in 2017), and I caved for $74.

Yes, 57433SG000. I should have asked for it back....

 

[AbsoluteZero]

Here's my reasoning for asking..... darts accepted. I've identified the DCM as a source of current drain that runs down the battery if I don't drive for 4 or 5 days so I removed the DCM fuse. The unit's backup battery is 7 years old. If it can no longer be charged I'm thinking the unit's charging circuit may stay energized causing the current drain... but I don't want to spend $50 for a new battery to find out.

 

[brucep]

I've identified the DCM as a source of current drain that runs down the battery if I don't drive for 4 or 5 days so I removed the DCM fuse. The unit's backup battery is 7 years old. If it can no longer be charged I'm thinking the unit's charging circuit may stay energized causing the current drain

Your logic seems sound.
I agree that pulling fuses is a great way to isolate parasitic draw down to a specific circuit.

Be cautious of the 'modules' communicating with each other and waking-up. Sometimes, whilst troubleshooting, you have to wait HOURS before all the modules go to sleep.... then opening a door will cause a wake-up signal thus messing up your troubleshooting.

Looks like a 18650 or 18500 at 3.7v may be acceptable to test my idea.

I would think as long as you MATCH THE TECHNOLOGY... whatever cell you use will be fine. I would be surprised if your original battery does not have some type of ID label on it.

What I mean is: If the original battery is Lithium-Ion, then ANY "Li" battery cell of similar size should work because they all are the same voltage and charging algorithm. (regardless of the physical size of the cell)

 

[Fibber2]

The only thing that struck me as slightly odd was the 3.2v rating on the battery walker shows. 18650 LiIon batteries (in my experience) are typically 3.7 volts with current ratings of 2000 - 3500 mAh. Ignore the advertising claims of 5,000-10k.

I have seen some 18500 LiPhosphate batteries with 3.2 v / 1100 mAh ratings. And there are 14430 cells with 3.2v but typically lower current ratings.

 

[brucep]

And there are 14430 cells with 3.2v

14430 cell is LiFePo4 (Lithium Phosphate)..... NOT the same technology as 18650 cells.

This is why I said to MATCH THE TECHNOLOGY. 😊

 

[Fibber2]

14430 cell is LiFePo4 (Lithium Phosphate)..... NOT the same technology as 18650 cells.

Yes, I meant Li Phosphate for the last two (should have made that more clear).

And that's the problem.... Most rechargeables in this class (18650, 18500 and 14430) that deliver 3.2 volts are LiFePo4 composition. Yes, it's a Li Ion cell, but not the same as the Li Ion (polymer) used in many 18650 cells, which are more typically 3.6-3.7 steady state volts.

So I'm seeing a mismatch here. The battery shown in @walker's post says: 3.2 volts / 1100 mAh / Li-ion Battery LFP. Assuming the F = Fe (chemical symbol for Iron). So I believe to match the technology we WANT to look for a Lithium Iron Phosphate battery!

When the OP pulls the DCM, we'll see the truth on what they are really putting in there.

 

[Rymar]

I removed the DCM from my 2019 Outback within a month after buying it in August 2019, because I find it intensely creepy that my car had a cellular modem, and 2 way audio access to the interior, which I couldn't control. Here is a photo of the battery. I unplugged the battery from the DCM before storing it. Still measures 3.34V. Not sure if the DCM for the 2016 models uses the same battery. Connector looks like some sort of 2 pin latching Molex connector, and the battery has foam tape to keep it from rattling in the compartment in the DCM.

 

[LogicalPosition]

I removed the DCM from my 2019 Outback within a month after buying it in August 2019, because I find it intensely creepy that my car had a cellular modem, and 2 way audio access to the interior, which I couldn't control. Here is a photo of the battery. I unplugged the battery from the DCM before storing it. Still measures 3.34V. Not sure if the DCM for the 2016 models uses the same battery. Connector looks like some sort of 2 pin latching Molex connector, and the battery has foam tape to keep it from rattling in the compartment in the DCM.
View attachment 556719

Oh Boy!
This topic and post piqued my curiosity. So I spent 30 minutes researching this DCM Telematics thing.
Apparently the DCM Telematics allows for internet access, 2 ways.

Is this for JUST the radio(i.e. Sirius streaming)? Starlink, as well?
Rymar, is big brother watching us with this DCM? How has the removal of you DCM affected the radio or performance of your vehicle?
I get a tad nervous when I hear Government spokenpersons PROMISE to remove ALL ICE Engines from America by 20XX.
And, I must replace a $65 battery every 7 years+-?
And, there is a parasitic draw from the charger relay if I don't?

I found this blurb on a Toyota Techinfo paper.

"The Data Communication Module (DCM) in the subject vehicles is equipped with software to identify the location of the vehicle using the Global Positioning System (GPS) to support features of the Safety Connect system*."

Should I presume that these DCM are a possible tool to locate SPECIFIC vehicles if necessary? Can a vehicle become incapacitated by another party?

 

[AbsoluteZero]

Only identified loss was the microphone doesn't work with the DCM disconnected. I get incoming calls but can't answer then when the phone is connected to the radio. All aspects of the radio still work. It's my understanding that later models control front speakers thru the unit and they stop working. I didn't renew Starlink but assume no features would work with the DCM disabled.
I had found the parasitic current drain to be in the 140-150ma range (using an el cheapo Harbor Freight VOM) Removing the DCM fuse dropped that to around 20ma and now I have no low battery issue of not driving for several days.
I wonder if the unit's antenna were disconnected it would accomplish the same thing as removing/disabling the whole unit ....... for those concerned over privacy. Won't solve the battery drain issue.

 

[brucep]

Should I presume that these DCM are a possible tool to locate SPECIFIC vehicles if necessary?
Can a vehicle become incapacitated by another party?

I fear the answer to both of your questions may be "YES"

Nearly every electronic device sold in America for 50 years has an FCC 'disclaimer' that it CAN be disabled using external means. (EMP protection is only on military electronics and illegal on civilian devices)

Now, things have become more invasive and not only RECORDS (think airplane "black box")... many vehicles can 'phone home' in event of accident. (General Motors vehicle are infamus for this 'feature')

 

[walker]

so back to the battery testing question....

for the dark current drain, subaru says to wait 15 minutes to rule out the DCM. Just to make sure your testing was accurate and it was this thing pulling power after it should have gone to sleep.

 

[Fibber2]

As stolen vehicle tracking is a part of the service, we can assume that two-way GPS is a feature of the DCM.

V2V and V2I has been included in a number of vehicles since 2015. Toyota introduced it first as they reportedly prepared it for the JDM and included it in other vehicles worldwide. It was originally on it's own band, but a few years back the FCC requested that it be moved to a cellular band for North American vehicles so that pedestrians and cyclist carrying cell phones would also be identified by the vehicle transmissions & monitoring. Makes sense. You want to know about someone about to cross the street at a 4 way stop-sign intersection just as you want self-driving vehicles to determine which vehicle moves first. So that's another feature of the DCM. Whether it's turned on by Subaru or remains dormant until the system is more mature is the question.

Now back to the BATTERY question. @brucep Are we in agreement that the correct aftermarket replacement backup battery is likely a 3.2 volt LFP (aka LiFePo4 / Li Phosphate) cell?

 

[brucep]

Now back to the BATTERY question. @brucep Are we in agreement that the correct aftermarket replacement backup battery is likely a 3.2 volt LFP (aka LiFePo4 / Li Phosphate) cell?

I cannot agree nor disagree.... What I have said is that the MEASUREMENTS and VOLTAGE of the original battery should provide hints to what type of battery (number and technology).

Surprisingly, Wikipedia has a fairly extensive chart which helps identify battery-number based on physical size.

https://en.wikipedia.org/wiki/List_of_battery_sizes

 

[Fibber2]

You are sounding more like a lawyer today than an engineer.

This is why I said to MATCH THE TECHNOLOGY.

The battery says right on it 3.2 volts, 1100 mAh LFP. Given those markings, it suggests that the OP likely needs a LiFePo4 / Li Phosphate replacement. We can probably imply the form-factor (diameter & length which is what many of the numbers like 16650 imply) with a little further study of options available that meet the basic stated specs.

But if you feel that I am wrong, please jump in and help?

 

[Rymar]

I know this thread is specifically about the DCM battery, but just to answer a few of the related questions about the removal of the DCM:

1) There have been no problems with the navigation GPS, or the stereo, or any other issues after the DCM was removed.

2) I needed a bypass connector to restore the speaker function, and hands-free microphone connection.
See this thread:

Disconnected cars: non-Starlink/LTE options

I would like to get a gen-5 with no (working) LTE/cellular radio, and I'm having trouble finding clear information on which trim levels either had no LTE radio or had it only as an option. (I'm deliberately not saying "Starlink" since it sounds like even that term is confusing.) 1) Which trim...

www.subaruoutback.org

3) My car now is much less vulnerable to being hacked, because there is no remote access. All Starlink functionality is unavailable, so both of the overhead SOS and info lights are out, and pushing the buttons does nothing. Any computer system hacking would required direct access to the CAN bus(es). Or maybe just the keyless entry system. But not through the cellular data connection.

4) There is a crash recorder (part of the ECM?) in Outbacks. But I don't think that data is sent through Starlink. I think there needs to be a direct physical connection to the car to download that data. And, perhaps surprisingly, I don't mind that. If there's a crash, and it's serious enough to require the black box data, then that data should be part of the inquiry.

5) Is big brother watching us? Well, yes, through many different devices (cell phones, for example). But "big brother" is really corporations, these days. And unlike in George Orwell's "1984", they have gotten us to pay for the privilege of being monitored and tracked. No, I don't wear a tinfoil hat, and all these corporations really want to do is keep selling you more stuff. But somehow, I just need to push things back a bit, and this is one way to do that. I know others see this differently, and that's OK too.

6) V2V (Vehicle to vehicle) communication is not part of the DCM capabilities. Its only means of communication is through a cellular modem, and "phoning home". Yes, your car has a phone number. And V2V cannot operate by one car dialing another car's cell phone number at an intersection. How would the DCM know the proper number(s) to dial? It would also be way too slow for accident avoidance.

If you have decided not to keep paying for Starlink, there is no reason to replace the battery. Just remove the DCM.

Back to the battery:
Soldering leads to a bare cell is non-trivial, because you can't use heat based soldering. These type of wired battery connections are typically made with resistance welding. And I agree, you need exactly the same voltage and current rating, and the same Li-ion chemistry, in order to avoid problems, including overheating and fire risk. I would just spend the $50 to get the OEM part.

 

[brucep]

You are sounding more like a lawyer today than an engineer.

How many engineers do you know? From my perspective, there are very few absolutes besides the laws of physics and mathematics. Engineering is simply applying those laws to do my bidding. 😊

Did I miss the post where the OP (AbsoluteZero) said their original battery is "3.2 volts, 1100 mAh LFP" ?
I have seen a couple other appenders talking about THEIR battery.