Do 30W USBC phone chargers kill Alternators?

crespoh69

Member
Hey guys, driving in to work today and my battery light came on. I just replaced the battery around June so I'm pretty sure it's not that. The weird thing is that it just happened to my wife's car as well about 3 months ago which is a 2007 Ford Focus and that turned out to be the alternator. The only common thing between her car and my V6 4runner is that we're both running a 30W USBC phone charger, actually it's the exact one from her car, I just moved it to mine. Is that too much for car alternators? It was a cheap charger but charges our phones quick so not sure if it's the charger itself or if it's not recommended to use then in cars or at least not in older cars.
 
Register to hide this ad
Hey guys, driving in to work today and my battery light came on. I just replaced the battery around June so I'm pretty sure it's not that. The weird thing is that it just happened to my wife's car as well about 3 months ago which is a 2007 Ford Focus and that turned out to be the alternator. The only common thing between her car and my V6 4runner is that we're both running a 30W USBC phone charger, actually it's the exact one from her car, I just moved it to mine. Is that too much for car alternators? It was a cheap charger but charges our phones quick so not sure if it's the charger itself or if it's not recommended to use then in cars or at least not in older cars.
30W is less than one headlight bulb. Or less than your brake light bulbs combined. That's not it.

-Charlie
 
Well, you need to voltage test your alternator with it running, and load test your batteries. That will actually diagnose your situation. 13.6-14.1 is ideal for charging voltage.

There is basically a 0% chance that your charger is causing this problem.... if it was pushing that kind electrical noise and RF energy, you'd probably notice it.

Just because the battery is fairly new, that doesn't necessarily mean anything.
 
You probably have brushes failing on your alternator. The average brush life is 180 to 250k.
If you have your alt replaced with a aftermarket autparts one. They may last a few years if your lucky. Best to check the charging system throughly and go from there. :)

Sent from my SM-A536V using Tapatalk
 
30watt charger pulling around 2.14amps at max charge. If this draw kills the alternator, problems were preexisting.

Is the power always on to the charger? Anything else drawing power when vehicle is off? Try checking total draw when everything is off, doors are closed. May need to give the vehicle 10minutes to allow computer to self power down. What is the amperage draw?

Check battery cables. Corrosion can develop below the insulation.
 
Is the power always on to the charger? Anything else drawing power when vehicle is off? Try checking total draw when everything is off, doors are closed. May need to give the vehicle 10minutes to allow computer to self power down. What is the amperage draw?

Check battery cables. Corrosion can develop below the insulation.

When the car is on, the power is on for the charger, or at least the little LED that shows you it's there, not necessarily that it's plugged into a phone and charging it if that's what you mean. When the car is off, all lights on the charger are off. For reference it's this one. Anything that'd be drawing power would be by BT OBDII scanner that I know keeps a small LED on all the time, I forget to unplug the thing, there's also a door open light on the dash that's always on, no matter if the doors are open or closed.

In the end, it did turn out to be my alternator though, I took it off and brought it to Autozone and they failed it. I was able to get on from amazon installed today though. Honestly, since it's happened twice with the same charger I'm wary of keeping the charger, how would I go about testing to see if it's drawing too much power? I've never used a multimeter before and would appreciate a youtube link on how to use it on our vehicles if possible.
 
When the car is on, the power is on for the charger, or at least the little LED that shows you it's there, not necessarily that it's plugged into a phone and charging it if that's what you mean. When the car is off, all lights on the charger are off. For reference it's this one. Anything that'd be drawing power would be by BT OBDII scanner that I know keeps a small LED on all the time, I forget to unplug the thing, there's also a door open light on the dash that's always on, no matter if the doors are open or closed.

In the end, it did turn out to be my alternator though, I took it off and brought it to Autozone and they failed it. I was able to get on from amazon installed today though. Honestly, since it's happened twice with the same charger I'm wary of keeping the charger, how would I go about testing to see if it's drawing too much power? I've never used a multimeter before and would appreciate a youtube link on how to use it on our vehicles if possible.


Dude..... are you even reading anything we've told you so far?

Further more, did you seriously take your alternator to AutoZone to be tested, and then not buy a replacement from them?
 
Dude..... are you even reading anything we've told you so far?

Further more, did you seriously take your alternator to AutoZone to be tested, and then not buy a replacement from them?


That is interesting they didn’t charge something for the test…..

OP you should fix/find what is keeping your door ajar light on.


Sent from my iPhone using Tapatalk
 
You probably have brushes failing on your alternator. The average brush life is 180 to 250k.
If you have your alt replaced with a aftermarket autparts one. They may last a few years if your lucky. Best to check the charging system throughly and go from there. :)

Sent from my SM-A536V using Tapatalk
This. A $20 brush pack. Plus, get that door problem fixed.
 
Dude..... are you even reading anything we've told you so far?

Further more, did you seriously take your alternator to AutoZone to be tested, and then not buy a replacement from them?

Of course they did. That's ok... Mostly, sadly the amazon alts are worse then the auto parts one. So they be changing it again soon from it failing a pile sooner then a denso would have or rebuilng your old one. :-)
 
If what you have plugged in to the charge port is too much for it, It would blow the fuse. So a good rule of thumb would be, if the fuse isn't blown, you are good to go.
 

Members online

Forum statistics

Threads
278,316
Messages
3,554,120
Members
248,016
Latest member
Advally Service

Trending content

Back
Top