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Help Phone not charging from car's cigarette lighter (USB port)

Pi

Pi

Member
'I bought this from eBay:

140097-01.jpg

• Input Voltage: DC 12V - 24V
• Output Voltage: 2 Sockets: DC 12V - 24V 5A,
USB Port: DC 5V ± 5% 500mA

usb cable attached to my laptop charges my phone but not when plugged into this thing.
the phone comes out of sleep mode but doesn't saying 'CHARGING'.
I have the original Droid.

the sockets works fine with GPS and dashcam.

so this usb port has enough juice just to power the phone but not to charge it?
or..?
 
lunatic59 said:
500 mA is probably not enough to charge your phone. 1A minimum and 2A if you use as a GPS is what I'd recommend.
Click to expand...

but my computer's usb ports are 500mA and it charges. the word 'charging' appears on the phone.

for this car charger, I've also only had the usb plugged in and the phone still doesn't say 'charging'
 
Have you actually put a meter on the output of the ports? It could be that one puts out 495mA and the other 550mA. If the amperage can't trip the charging circuit, it won't charge. Another possibility is a non-standard pinout for the charging port or cable.
 
Is it on wifi when plugged in to the laptop?

The phone could be using more power in mobile radio mode than on wifi plugged into the laptop. In fact, that's almost a certainty and more so on the earlier phones.

Even if the car charger is perfect, if it's already drawing more power than the charger can provide, it's not going to charge.

If true that it's on wifi when plugged into the laptop, turn off wifi, see what happens. If it stops charging, there's your answer.
 
lunatic59 said:
Have you actually put a meter on the output of the ports? It could be that one puts out 495mA and the other 550mA. If the amperage can't trip the charging circuit, it won't charge. Another possibility is a non-standard pinout for the charging port or cable.
Click to expand...

no, don't have a meter.
the same usb cable charges my phone from the laptop usb port fine.

ahh.. so amperage needs to exceed a threshold?
 
Try it in your car on airplane mode. If no luck, try it turned off.

If it starts charging either way then luna's speculation is most likely correct, the charger isn't delivering the rated power.
 
Just out of curiosity, do you still have the original charger that came with the Droid? It would interesting to see what it was delivering in terms of power.
 
There you go. 500mA is under spec'ed. Best case scenario, it will charge but very slowly. Worst case ... it doesn't work at all.
 
lunatic59 said:
There you go. 500mA is under spec'ed. Best case scenario, it will charge but very slowly. Worst case ... it doesn't work at all.
Click to expand...
Most phones will charge slowly but reasonably enough off of a pc usb port and as he mentioned, his is no exception. Those are locked at 500 mA in all cases.

I think that it's the car charger. If it delivered the rated power, identical to a pc usb port, then there would be no difference in charging as the phone configuration and charging cable has been held steady.

Therefore, the car charger isn't putting out what it claims.

Btw - a 1 A car charger, typical lighter plug deal - won't harm that Droid.

PS - I only trust monoprice.com for those things or pay extra at the carrier store. If you get any car charger that exceeds the rated voltage, your phone is toast.
 
Last edited:
EarlyMon said:
Try it in your car on airplane mode. If no luck, try it turned off.

If it starts charging either way then luna's speculation is most likely correct, the charger isn't delivering the rated power.
Click to expand...

airplane mode = same. does not say charge on the phone. will try turning it off next.

is there an app that measures the amount of current going into the phone?
 
Yep.

Check out "3C Toolbox"

https://play.google.com/store/apps/details?id=ccc71.at.free

The first screen is its own ad, hit the back key.

Choose the Battery Mgr.

For setup, leave it on automatic.

It will show negative and positive current flow to show how much the battery is providing or being provided.

Use it unplugged at first to see what I mean, and of course, not while your battery is at full charge for this step or the next ones. Not at full charge on the battery is an essential condition for what you want to see.

Start Battery Mgr.

View battery page unplugged with less than full charge.

Plug in to laptop to see how the monitor is supposed to look with a 500 mA @ 5 V charging source. Leave it for several seconds so you're sure that you've seen the state change.

Unplug. Observe.

Plug into car. Several seconds to be sure of what you're seeing.

It's OK to leave the battery monitor page up during the whole deal and I'd recommend it so there's no confusion.

Hopefully that app will work for you.

I can predict the results but let us know what you find. :)
 
Pi said:
Earlymon,

3c Toolbox:
'your device isn't compatible with this version' :(
Click to expand...
Sorry about that.

Well - the bottom line is - your phone is drawing less than 500 mA during normal use.

Your car charger is supplying less than 500 mA and less than what your phone is drawing.

Car electrons are the same as laptop electrons, that's why I'm sure.
 
As an electrician - all things electrical/electronic are supposed to fall under "U.L. listing" - Underwriter's Laboratory.. And many things made outside the US aren't actually built to UL specs, some even have fake UL tags.. For example: the circuit may be rated for a certain amount of power, but the undersized wires won't carry the load correctly, restricting the power flow (most common with lamps produced outside US, having undersized wires that get hotter quicker) so even tho the lable says one thing, it won't work correctly. THAT'S why ppl are telling you to check the power source with a meter.. And I agree with most everyone else - most likely the power port itself
 
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