Voltage Drop at SDS100 Lower USB port

W4EMS

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Have gotten the Low USB power warning a few times of late while mobile. Have checked the USB adapter and cable voltage which read 5.0-5.1 fairly consistently.
The rig however shows the voltage at 4.4-4.6, occasionally as low as 4.2.
I did tighten the male USB adapter and it has a more snug fit so will be watching to see if this helps.
Just wanting ask if others see a similar voltage drop which may be possibly be due to small wiring in the after market angle USB adapter cable.
Thanks.
 

tvengr

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Most likely, the USB adapter you are using does not supply enough current. Turn off Charge While On if it is enabled.
 
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mc48

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Smaller cables do impact the voltage but the problem may be as simple as cleaning the contacts on the cable or scanner with IPA or contact cleaner. I had a similar problem with a cable when plugging into my laptop and cleaning the contacts fixed the problem and it has never happened again.
 

whooey

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Amazon has a lot of different USB's as far as head angles and whatnot. I almost guarantee you will find one that will fit your application without having to use adapters. Found a perfect one for my truck, works great.
 

RandyKuff

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If your reading the voltage from your usb adapter not connected to the scanner, not a valid value of the voltage
because it's not under load. It is open circuit.

Something like this will show what the voltage is under the load of the scanner...

 

jonwienke

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Agreed. Open circuit voltage means nothing. The only relevant reading is the voltage at the scanner, downstream of the cable. Both the cable and USB port have to be capable of handling 2A of current.
 

W4EMS

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Thanks all. A 3 amp output USB should suffice, will revisit the cable. Supposedly the quick charge cable handle more current but have not found one with a down angle. And yes totally agree open circuit voltage just no way to check on load (other than the SDS100).
 

gmclam

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I use the detailed display and added the internal USB measurements, there is one for each USB port. It shows what the scanner thinks the voltage is. I've found you need to keep the cable length to 3' or less or use one with LARGE conductors (hard to find).
 

mc48

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I use a 10' cable with no problems it has #24AWG conductors for power and #28 for data, Monoprice from Amazon. (not a down angle)
 

hexagon_keyhole

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I use the detailed display and added the internal USB measurements, there is one for each USB port. It shows what the scanner thinks the voltage is. I've found you need to keep the cable length to 3' or less or use one with LARGE conductors (hard to find).
You would think the stock cable from Uniden would be up to par. I used the stock cable and stock AC USB Power Adapter that came with it, never got it to the full 5V. I took a microUSB cable I had for a phone and plugged it in to the stock power adapter, and it was reading 5V easy. It’s definitely the cable.

I use a 10' cable with no problems it has #24AWG conductors for power and #28 for data, Monoprice from Amazon. (not a down angle)
Was this for miniUSB or microUSB? And you had no voltage drop?
 

jonwienke

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I used the stock cable and stock AC USB Power Adapter that came with it, never got it to the full 5V.
Your cable/adapter may have been defective. In most cases, the cable and adapter that come with the SDS100 are usable without getting voltage errors, even if charging while the scanner is on.
 

mc48

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You would think the stock cable from Uniden would be up to par. I used the stock cable and stock AC USB Power Adapter that came with it, never got it to the full 5V. I took a microUSB cable I had for a phone and plugged it in to the stock power adapter, and it was reading 5V easy. It’s definitely the cable.



Was this for miniUSB or microUSB? And you had no voltage drop?
Mini USB, I haven't measured the voltage, but with the original cable and an extension it would never charge and would actually discharge the battery when running, when I turned the unit off it would charge until the green led illuminated. The new cable allows me to charge with the unit running, I'm using the Uniden supplied PS.
 

hexagon_keyhole

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Your cable/adapter may have been defective. In most cases, the cable and adapter that come with the SDS100 are usable without getting voltage errors, even if charging while the scanner is on.
Oh, I think I might have added some confusion. Allow me to clarify. So I don’t get any charge warnings or errors. I’ve noticed that with stock mini-USB cable and stock AC adapter, according to the onboard USB voltage monitor I get roughly 4.96V. I notice the battery voltage seems to go up and down (4.17, goes to 4.18, goes back to 4.17), but it doesn’t appear to drain downwards and the mini-USB power doesn’t seem to go to 5.0V. If I use the same AC adapter with a micro-USB cable however, it goes full 5V and the battery voltage is stable, no flipping.

I believe when I see the battery voltage flipping, it’s because I am using the external battery charger and the charger doesn’t charge the battery to full voltage (4.20V?). It’s not a major concern for me, as when I want to power only the radio I use a micro-USB cable to supply the scanner with the full 5V.

Hope this clarify things!

EDIT: The mini-USB cable that came with my BCD436HP and SDS100 don’t go to full 5V (with the stock USB charger) and does the battery voltage flipping. I have a really short 6” mini-USB cable from a old portable hard drive, and I plugged it into the stock USB charger and the scanner is now showing 5.12V, no battery voltage flipping. Quality and length of cable matters!
 

W4EMS

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I've found you need to keep the cable length to 3' or less or use one with LARGE conductors (hard to find).
Hard to find is correct. Open to any suggestions.
I do have a Monoprice 6 ft cable just prefer the down angle yet may need to revert back. Waiting on the weekend.
 

kd2pm

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I am having this issue all of a sudden and having used the exact same cables and adapters has me wondering if its not the battery causing it.

I tried 2 different cables that have always worked in the past and I have an Anker 5 port USB power bank that has plenty of power. Gonna do some testing with other cables and adapters but if its happening with multiple cables and adapters..gotta believe something is afoot!
 

W4EMS

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After reading a few more posts I took my wireman pliers and gently (very gently) "tightened" the radio end of the cable.
As it was intermittent not positive if that fixed it but so far so good.
Very hard to find 24 ga USB cables. especially with an angled tip.
I have now checked under load and USB power source keeps 5.1 volts while the extension loses 0.5 volts and the final run (3 ft with an angled tip) loses another 0.1-0.2 V so looking at a remedy to get rid of the extension cable.
Guess need to get used to USB ports as they seem to be the goto power source these days.
 

kruser

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These StarTech cables have all the angle options, and heavy enough wires to handle the SDS100 charging while running:
Yep, I also use these same cables of the 1 meter length and they have always worked fine, including charging while operating the SDS100.
Of course the source power supplies these cables plug into are going to be different for each user so some could still see problems with them.
 
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