Hey folks, I have a very weird problem that I could use your help with.Last night I discovered that 2 of our cell phones and 2 of our chargers won't work. It's not a problem with the phone or the chargers. It seems to come down to the amount of juice that the phone requires to charge. Here is what is happening:Charger A (long cord) - doesn't charge either phoneCharger B (Samsung quick charger) - doesn't charge either phoneCharger C (Standard charger with a very short USB cord) - charges my Samsung Galaxy S3 (low power requirement); doesn't charge the Note 4 (high power requirement)It's not the phones, because the Note 4 charges off of my computer just fine.Yesterday I plugged in a UPS with automatic voltage regulator for the first time, and it was after then that the phones stopped charging. I unplugged the UPS but the problem persists.As near as I can tell all the other systems in the RV are working properly, and no breakers are tripped.Does anyone have any ideas? Is it possible that the UPS drew too much power and damaged something?Edit: P.S. - I don't know a lot about electrical systems. I don't have a voltmeter, but I've tried a lot of outlets. Also, the UPS is reporting that it's receiving adequate power.

Guessing by process of elimination (of hair on head).You can do this the hard way or the easy way. Your choice...Google USB METERS then GOOGLE USB (to whatever) adapters are needed to connect to the phone or other gizmos. These things are CHEAP and worth their weight in gold.Plug the USB meter inline.Tah-Dah!Is voltage anywhere NEAR 5.0 volts when connected to your device?GIZMOS have a threshold voltage a bottom voltage limit below which they will not work. It isn't the wall wart - it is the gizmo.I have an LED floodlight charger that does the very same thing. Not the wall wart the controller within the floodlight.

At work we had a lot of problems with bad contacts on the end of cheap micro USB cords. Try a new cable.

Check to see if you tripped a GFCI receptacle.Use known good appliance in receptacle to test for presence of 120 volts AC.

About the only thing A UPS UNIT may do is trip some GFCI circuits. I am assuming you are wanting power from the 120VAC outlets and not the 12VDC circuits.. Normally when parked you only have the 12VDC circuits working as the 120VAC is only powered up by plugging into the shore power pedestal or being run off the generator...Check your GFCI wall receptacles that have the PUSH BUTTONs in the center and see if one of those has tripped. Usually several 120VAC receptacles down the string will go off when the GFCI one gets tripped.. You should have a GFCI receptacle whereever water is located like the kitchen sink area, the bathroom area, the wash up area sink in the bedroom hallway etc... I suspect yopu will three of these installed in your trailer.This is what a GFCI 120V RECEPTACLE looks likeAlso it is kinda neat to fill out your signature line or profile line to show what RV items you have. No one can help very good not knowing what RV UNIT you are talking about...Roy Ken

Sorry Bud - You type faster than I do haha....Roy Ken

Weird electrical problem - 2 phones won't charge

Ductape
Explorer
Jul 26, 2015
Thanks for posting the resolution, too many posters only give the problem and disappear. Glad it turned out to be inexpensive
enblethen
Nomad
Jul 26, 2015
Thanks for the update!
jayspi
Explorer
Jul 26, 2015
So this is what the deal was...and let me preface it by saying that I feel like an idiot, especially since I work in the tech industry lol.

We're in Florence, OR, right now, which is known for its sand dunes. We'd been out and about quite a bit and I think some fine grains of sand ended up making its way into several of our charging cables. It was too fine to see, even with a high powered flash light. Apparently the contacts on the Galaxy S3 and Note 4 are much more sensitive than the S5, which is why my wife's phone was still charging and the other 2 weren't.

I guess it was just an extreme coincidence that they both reached the tipping point the same evening I connected the UPS.

So @ducttape, I owe you an apology for this:

jayspi wrote:
Ductape wrote:
At work we had a lot of problems with bad contacts on the end of cheap micro USB cords. Try a new cable.

I'm 99% sure it's not the contacts. I shouldn't have that problem on 2 chargers at once, and it also wouldn't explain why one phone charges off the 3rd charger and the other doesn't. Unless the contacts went bad and the charger in the phone got dirty / went bad at the same time. That's just too coincidental...

After many years in the tech industry I've learned that it's best sometimes to just admit that you were wrong, and I was :)

But during this process I learned a lot about electrical systems in an RV, so it's a definite win. I used to get stressed about all this stuff until I learned to treat it all as a learning experience.

Thanks to all of you for your help!
jayspi
Explorer
Jul 25, 2015
Figured it out! Have an appointment now but will post what happened later. Thankfully it wasn't anything with the RV systems!
MEXICOWANDERER
Explorer
Jul 25, 2015
Wanna get dizzy? Connect oscilloscope to typical wall wart output. Stare at screen.
landyacht318
Explorer
Jul 25, 2015
So it appears the 5v wall wart USB outlets are fried.

A future solution can be a 12v to 5vUSB outlet, that way they phones still charge if the power goes out.

I've been very happy with this unit:

http://www.amazon.com/Blue-Sea-Systems-Charger-Socket/dp/B0082CXEI8

I also have this USB power meter. It allowed me to see why some USB sources and cable combinations were so poor and others would charge much faster.

http://www.amazon.com/Jelly-Comb-Universal-Multi-meter-Voltmeter/dp/B00NHHP06C/ref=sr_1_sc_1?ie=UTF8&qid=1437804502&sr=8-1-spell&keywords=jellycomb+usb&pebp=1437804505454&perid=1AWG6NK9NDKQH9QWFKP4

That model actually counts amp hours consumed on several different devices, but that feature is a bit clunky.

Here is a professional review:

http://lygte-info.dk/review/USBmeter%20KCX-017%20UK.html

I've also bought a bunch of 1' long Micro USB cables. I've found the short length to be way more convenient. Anker brand on Amazon. These pass data and have the least voltage drop, and when I use it with that Blueseas 12v to 5vUSB power supply, charge My S4 Mini significantly faster than the Samsung provided cable and 120Vac USb power supply.
wcjeep
Explorer
Jul 25, 2015
Longer USB cords tend to have problems charging modern devices. I stopped buying generic cords. I normally buy Samsung or Motorola cords/chargers from Amazon. There are specific charge cords available. They do not pass data.

I installed a power outlet in the towrig for daughters gadgets. Later I pulled the fuse and placed a multimeter inline to measure amperage. This allowed me to test different devices with different chargers and cords.
MEXICOWANDERER
Explorer
Jul 24, 2015
I much prefer "The 12-Volt Doctor". It is better written, has had many more years for sailboat owners to scream "That ain't right" and for the author to revise the error. Sailboats are extremely similar in concept to an RV except their systems are more extensive and thus harder for a unschooled owner to troubleshoot. Nav lights are clearance lights, the anchor winch motor can be likened to stabilizers or a slide out, alternators are alternators, and batteries are batteries. It even provides some Dick & Jane level projects I find fun-to-do.
jayspi
Explorer
Jul 24, 2015
MEXICOWANDERER wrote:
A USB plugs inline with your USB cable. Useless for anything else. But checking USB with a conventional meter is not fun. You need both types plus a wall meter for the rig battery and another meter for AC voltage. Sounds intimidating but today's prices are reasonable for all.I prefer handheld meters with lots of manual settings on the dial. Chinese fool engineers love to make mv, ohm and other symbols #1 font on the LCD panel so a microscope is needed to see what range an autorange hand held meter has chosen. With manual there is no ambiguity.

Thank you for the info. I'll do a bit of research. I also think I'll go ahead and get a book that I saw on RV electrical systems. It's time to learn about this stuff lol
MEXICOWANDERER
Explorer
Jul 24, 2015
A USB plugs inline with your USB cable. Useless for anything else. But checking USB with a conventional meter is not fun. You need both types plus a wall meter for the rig battery and another meter for AC voltage. Sounds intimidating but today's prices are reasonable for all.I prefer handheld meters with lots of manual settings on the dial. Chinese fool engineers love to make mv, ohm and other symbols #1 font on the LCD panel so a microscope is needed to see what range an autorange hand held meter has chosen. With manual there is no ambiguity.

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Weird electrical problem - 2 phones won't charge

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