12v charger blows USB plugin

[carlager]

I have installed a 12V car charger in the cockpit in order to charge our iPad mini when using it as a plotter.

The iPad mini loaded fast to 100% battery using a USB lightning cable on a USB car plugin (12-24 volt on 2,4 A) and a - both approved by Apple.

When I unplugged the USB car plugin and plugged it back again it had stopped working (no light and no charging)

I have measured voltage on the car charger to 13,5V

Any Ideas what is wrong ?


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[hellosailor]

Your boat is not Apple approved, so Apple has shut down the equipment you connected to it. (G)


Either your charger is not making good contact with the power socket (not "car charger") that you installed in the cockpit, or there's probably an internal fuse that you blew in the charger. See the manual, often the tip of the charger unscrews to reveal hidden spring-loaded fuse inside. Why that might have blown, another issue.


If it is new and covered by warranty, let Apple deal with it. If there's nothing obviously wrong...the Apple stores still have a genius bar to deal with that?

[rwidman]

What do you mean by "12V car charger"?

[smac999]

do you mean a 12v cigarette outlet?

a "car charger" is something you charge a battery with using AC power.

[carlager]

I mean a 12V cigarette outlet

[carlager]

Thanx for you replies.

A correction

It was a 12V cigarette outlet I installed and NOT a battery charger as I wrote.

Some further information

1. The new outlet gives 13,5V (excludes a blown fuse and a broken outlet)

2. The outlet is wired from another 12V cigarette. A small lamp in the engine room is also wired from this outlet.

When checking this old outlet this morning this outlet turns out to have died. The small lamp still works and there is still 13,5V on the newly installed outlet.

Could the wirering be the problem ?


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[Reefmagnet]

Those 12 volt phone / tablet chargers often have a fuse behind the positive "prong". You unscrew the end of the male plug like a bottle cap to get access to the fuse. It's usually what is known as a 2AG style. This could be the problem if the 12 volt socket checks out.

If not, check for high resistance / voltage drop by measuring the DC voltage at the socket with the charger plugged in.

[athene]

Have you checked the polarity?

GORDON KNIGHT

[rwidman]

Try your Ipod in the outlet in your car. Does it work? If so, the problem is on the boat. If not, the problem is with the Ipod or the cable.

Get another 12 volt plug in device such as a fan or light. Plug it into each outlet on the boat. Does it work in both, one but not the other or neither? This will tell you where to start troubleshooting the wiring.

[jhstacy]

I have seen this before. Check the polarity with a volt meter and make sure positive and negative are not reversed. if they are reversed, you will blow many USB chargers. When I saw it, someone had connected the black wire to positive and the red wire to negative

[windwalkr]

A fan would say if the plug was working, another problem which may be occuring is the rectifier by/on the alternator may be letting an AC signal through. This could also damage the charger. Also, if your multimeter has a trigger function you may be able to look for voltage spikes. Does the bay light flicker? A light and a fan will not show subtle power problems which could affect the 12v-5v charger.

[Howard_Sr]

A review of the USB 2.0 Charging port found on the internet at;
USB - Wikipedia, the free encyclopedia may help you.

A brief summary is that a standard USB 2.0 port can provide current up to 500 mA in 100 mA increments with digital negotiation, e.g. don't plug in anything that requires more than 500mA, or anything that cannot digitally negotiate with it.

"A USB 2.0 Charging Port can supply currents between 500 mA and 1.5 A without the digital negotiation. A charging port supplies up to 500 mA at 5 V, up to the rated current at 3.6 V or more, and drops its output voltage if the portable device attempts to draw more than the rated current. The charger port may shut down if the load is too high."

Two USB charging ports can be coupled with a Y cable to provide up to 3 A.

Note that the NavAssist Marine-PC has 2 X Yellow USB 2.0 Charging Ports.
Cheers,
Howard_Sr

[carlager]

I have identified a polarity error In the wiring to first 12V socket In the circuit.

After changing the wiring on this socket there is now the same voltage on all 12V sockets in the curcuit.

I hope this is why the USB charger was blown,

Thanx to everybody for contrubuting to solving the problem.




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