SDS100/SDS200: SDS100 “Low USB Bus Voltage”

[manlius]

I have been thoroughly impressed and overjoyed with the performance of my SDS100 since receiving it several weeks ago. I’m on the road every day traveling throughout Michigan’s LP, northern Indiana and Illinois. I use the Uniden GPS and power it with the Qualcomm Certified QC3.0 Quick Charge Adaptive 4 Port USB Fast Car Charger 35W. Although it is a 4-port charger, I seldom have more than 2 ports in use. This has been working perfectly until last Friday, when I started receiving this warning message intermittently:

I have checked the voltage at the truck’s outlet and verified 13.8v and plenty of current capacity (2’ run of 12 gauge wire, independently fused single circuit fed off 3 fresh Group 31 batteries wired in parallel by way of a 6’ run of 0 gauge cable to a lightly used junction block). The radio is running Main: 1.03.01, Sub: 1.01.03. I get the message regardless of whether “Set Charge While On” is enabled or disabled. I decided to check an alternate power source by powering it off my fully charged laptop which was also plugged in to 120V, but still the issue persists. My next option is to eliminate the GPS and just plug the radio in. I’ll give an update on that shortly. Has anyone else had this issue? Any suggestions? Thanks in advance.


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[Hit_Factor]

Power cable wires are too small of a gauge. At least that's my bet.

Look for USB cable with larger wires.

Not sure why it's just know manifesting the problem.

 

[jonwienke]

The USB cable or 12V-USB converter are the most likely culprits. Most USB cables can't handle the current draw of the SDS100.

 

[manlius]

Thanks, guys, for your quick replies. It’s gratifying to know that my initial thoughts align with both of yours.

To Hit_Factor, I assume that you are referring to just the USB cable and not the wires feeding the outlet it is connected to, which are certainly more than adequate.

And to both you and Jon, the USB cable is the Uniden factory part designed and called out to power and connect both the radio and GPS. The cables are new, the cables and GPS stay in place and are well supported, meaning they have not been subjected to any flexing or undue stresses. The only thing that moves is the radio itself when I put it in and take it out of the truck. It all worked great for several weeks. If we assume that Uniden designed the cables and connectors with the usual percentages of engineering tolerance, is there possibly something internal to the radio that might be a cause? I’m certainly aware of your experience, Jon. I can’t speak to yours, HF, but you do sound knowledgeable. Im all ears.


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[jonwienke]

I would look at the USB converter if you're using the Uniden USB cable. If you have a mini-USB cable that came with a tablet or other high-drain device try that, but a lot of cables simply aren't beefy enough to handle the SDS100 current draw.

The 12V wiring is not likely to be the culprit. 24-gauge is common for good USB cables, and I fabricated a 10-foot 22-gauge USB cable that powers the SDS100 just fine. So 12-gauge wires running at 12V is beyond overkill just to run the SDS100. Do you have anything else running off those wires?

 

[troymail]

There have been multiple discussions about various power and heat issues in various threads... one being:

https://forums.radioreference.com/uniden-tech-support/373090-not-charging.html

I know this thread was about charging but this low voltage thing (as well as other items) came up in the discussion.

The radio does seem to be extremely sensitive to both voltage instability/fluctuations and heating issues.

FWIW - in the past, I've had some issues with multiple devices plugged into a unit that has multiple USB ports - some scanners complained when I plugged my Samsung phone.

From what I've seen, you can expect to have these problems when attempting to power multiple devices at the same time - even more so under high(er) heat conditions and possibly also when the vehicle is not running.

 

[rfwyzard]

Adafruit.com. USB Charger Doctor part number 1852. Inline USB meter. reads voltage and current. $7.50. It should tell you exactly what's wrong, no guessing.

 

[manlius]

Here is a picture of the only cables capable of connecting the SDS100 to the Uniden GPS and the configuration is presumably designed to power both. The Uniden BC-UTGC has a standard USP plug that has 2 cables coming out of it. One leg has the mini-USB that plugs into the radio’s charge port. The other leg has the 6-pin female connector that matches the male connector of the GPS puck.

The only way to power the GPS is to plug the USB into a suitable power source and have the 6-pin connectors mated (excepting the cable configuration used with the BCD436HP). The only way to feed the GPS signal to the radio is to plug the mini-USB connector into the radio’s charge port, which also can charge the radio if “Set Charge While On” is enabled. As far as I know, there isn’t an alternate aftermarket cable with heavier wires available. And, I have to expect that Uniden would not market this cable unless it was capable of doing its prime function. The Qualcomm QC3.0 Quick Charge Adaptive 4-port USB Fast Car Charger is rated at 35 watts with port 1 capable of 5v @ 3.5amps. As stated, I seldom have more than 2 ports in use. Most of the time it is just powering the radio. I also stated that I tried powering by way of a fully charged laptop that was also plugged in. As far as heat is concerned, I have an a/c vent blowing on the radio. The GPS puck, on the other hand, is sitting on the dashboard where the sun gets to do its will. Short of giving Jon my hard earned money (I’m Dutch. I take pills for it, but they haven’t started working yet) and sending the radio to him for an internal GPS mod, does anyone have a theory that hasn’t been mentioned? Thanks again!


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[Hit_Factor]

After replying to the OP and suggesting wire gauge may not be sufficient.

I found my sds100 displaying the same message in my car. It was hot. I've never seen this message before. As a side note, the radio should have auto powered off, but it had not.

Sensitive may be a very accurate description. I will install a 2.4 amp USB port this weekend. Current port specs are unknown.

 

[SteveSimpkin]

Here is a picture of the only cables capable of connecting the SDS100 to the Uniden GPS and the configuration is ***presumably designed to power both***. The Uniden BC-UTGC has a standard USP plug that has 2 cables coming out of it. One leg has the mini-USB that plugs into the radio’s charge port. The other leg has the 6-pin female connector that matches the male connector of the GPS puck.

Well the Uniden BC-UTGC cable was designed to power the Uniden GPS puck and the *BCD325P2* scanner when it was introduced. The BCD325P2 scanner, however, draws much less current than the SDS100. What is odd is that this combination appeared to work ok for the past few weeks.

As a test can you take this SDS100/GPS setup with all of its cables and plug it into the USB power supply that came with the SDS100 instead of your USB car power supply?
If that works ok then I would say your QC3.0 Quick Charge Adaptive 4 Port USB Fast Car Charger is not able to provide 5V at the current required by the SDS100.

If this test still has the "Low Voltage" problem then try using the Mini-USB cable and power USB power supply that came with the SDS100 (without the GPS).
If that works, then there may be a problem with the Uniden BC-UTGC cable.

If this test still has the problem then there may be something wrong with the SDS100 itself.

 

[jonwienke]

Another possibility is that the heat in the car is diminishing the USB adapter's ability to supply its rated current and voltage to the USB ports. The only way to know for sure is to put a meter on the USB port and see the USB voltage and current when the scanner shows an error. This is the best one I've tried so far:

https://www.amazon.com/gp/product/B01KTV9RHQ/

 

[manlius]

...
I found my sds100 displaying the same message in my car. It was hot. I've never seen this message before. As a side note, the radio should have auto powered off, but it had not...

That’s crazy, Hit_Factor!! If I were a conspiracy theorist I would now be thinking that there was a time-sensitive virus/Easter egg in the last firmware update! But, I’m not a conspiracy theorist, thank goodness.

The heat thing is interesting, though. The radio generates heat just from being on. Charging adds more. My truck is quite literally a solar collector, although I have a makeshift shade over my routing gps so I can see it, and I also aim one of my a/c vents at it to help control the temperature. I’ve got a point-and-shoot thermometer that I’ll take along over the next couple of days, and I’ll do a little more testing.

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[manlius]

More great suggestions. Regarding alternate sources of power, I did try powering it from my laptop with no difference. I just pulled over and moved the cable to a usb outlet on my 2000 watt inverter. I’ve got about 30 miles to go to get home. I’ll see if anything changes.


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[SteveSimpkin]

More great suggestions. Regarding alternate sources of power, I did try powering it from my laptop with no difference. I just pulled over and moved the cable to a usb outlet on my 2000 watt inverter. I’ve got about 30 miles to go to get home. I’ll see if anything changes.

I don't believe most laptops would be able to supply the 1 to 2 amps of current needed by the SDS100. Most older laptops with USB 2.0 ports top out at 500mA (1/2 Amp) unless the ports are designed for charging.
https://en.wikipedia.org/wiki/USB#Low-power_and_high-power_devices

 

[maus92]

I don't believe most laptops would be able to supply the 1 to 2 amps of current needed by the SDS100. Most older laptops with USB 2.0 ports top out at 500mA (1/2 Amp) unless the ports are designed for charging.
https://en.wikipedia.org/wiki/USB#Low-power_and_high-power_devices

My Dell Latitude E7440, sort of a low-mid range i5 with USB 3.0 ports cannot charge my SDS100 if the battery has been significantly drained. It will run and maintain the charge of the SDS100 when the battery is at a high state of charge however. The USB 3.0 spec is 900ma per port, but Dell's implementation only supplies 500ma - so not enough current.

 

[maus92]

I have been thoroughly impressed and overjoyed with the performance of my SDS100 since receiving it several weeks ago. I’m on the road every day traveling throughout Michigan’s LP, northern Indiana and Illinois. I use the Uniden GPS and power it with the Qualcomm Certified QC3.0 Quick Charge Adaptive 4 Port USB Fast Car Charger 35W. Although it is a 4-port charger, I seldom have more than 2 ports in use. This has been working perfectly until last Friday, when I started receiving this warning message intermittently:

I have checked the voltage at the truck’s outlet and verified 13.8v and plenty of current capacity (2’ run of 12 gauge wire, independently fused single circuit fed off 3 fresh Group 31 batteries wired in parallel by way of a 6’ run of 0 gauge cable to a lightly used junction block). The radio is running Main: 1.03.01, Sub: 1.01.03. I get the message regardless of whether “Set Charge While On” is enabled or disabled. I decided to check an alternate power source by powering it off my fully charged laptop which was also plugged in to 120V, but still the issue persists. My next option is to eliminate the GPS and just plug the radio in. I’ll give an update on that shortly. Has anyone else had this issue? Any suggestions? Thanks in advance.


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It's possible that the USB cable has developed a fault / kink / damaged conductor, or the charger itself is about to fail. Try a different USB cable designed for a tablet (heavier gauge wire,) and a different 5V source. We've had good luck with these charger adapters, although they are a bit dim in daylight (not unlike the SDS100):

Flight Gear Dual USB Charger - from Sporty's Pilot Shop

 

[manlius]

It's possible that the USB cable has developed a fault / kink / damaged conductor, or the charger itself is about to fail. Try a different USB cable designed for a tablet (heavier gauge wire,) and a different 5V source. We've had good luck with these charger adapters, although they are a bit dim in daylight (not unlike the SDS100):



Flight Gear Dual USB Charger - from Sporty's Pilot Shop

Uniden cable (specific to GPS with 6-pin Din jack on one end for connection to the gps, standard usb for power in the middle and mini-usb on the other end for connection to the radio) is 4 weeks old, ordered with radio and not mishandled at all since being put into service. Qualcomm smart charger is also brand new. I did buy 2 of these, so I will switch to the other one and see if problem persists.


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[maus92]

Uniden cable (specific to GPS with 6-pin Din jack on one end for connection to the gps, standard usb for power in the middle and mini-usb on the other end for connection to the radio) is 4 weeks old, ordered with radio and not mishandled at all since being put into service. Qualcomm smart charger is also brand new. I did buy 2 of these, so I will switch to the other one and see if problem persists.


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I do not know the internal wiring of all the connections and connectors, but does the GPS feed into the scanner using the mini USB port? I wonder if you could find a USB mini to USB micro adapter to feed the GPS signal to the radio using the micro connection, and then have n additional USB power cable for the radio? I'm also curious if the GPS cable was actually designed for the SDS100, since it has a high current requirement, and previous radios did not.

Again, I have no idea of the internal connections / requirements for the GPS / SDS100 configuration.

 

[RF23]

I think Upman has stated that the GPS must be plugged into the USB2 or mini USB port on the SDS 100.

 

[K9JLR]

Has anyone found a commercially available, longer cable, e.g., 10+ ft., that works to handle the current draw?

I bought a longer 15-foot "high performance" USB 2.0 cable online and it is having the same issues. It's a 28AWG + 24 AWG gauge cable, since I needed something longer for home/desktop use.