Weird problen charging apple devices

[nvidia]

So i found my ipod touch not used in a couple of months  plugged it in to charge via a non apple power brick held down power button it showed the battery and lighting bolt for 3sec and went away left it for 5hrs but it wont turn on thought maybe the cable was broken so tried it with my ipod nano 3rd gen it woud not charge and my fake ipod nano also would not charge got another cable also would not charge tried a couple power bricks with no luck so tried the usb slot on my pc and both the fake and real ipod nano charge fine

What could cause this as charging my ipod touch via pc would take forever due to being  low mA

[james_s]

IIRC Apple chargers have a resistor in the charger connected to the USB data pins that tells the device the capabilities of the charger. Aftermarket chargers may not have this.

[kripton2035]

the default charge current of these devices is 500mA. if you install the correct resistors between the data pins, you can force 1A or 2A or current.
anyway if it charges with the PC, it should charge also at the lowest current, with the aftermarket chargers.
you should try independently the charger(s) tha cables, the devices. also a small usb current testing device is usefull to have.

[tooki]

IIRC Apple chargers have a resistor in the charger connected to the USB data pins that tells the device the capabilities of the charger. Aftermarket chargers may not have this.

Almost any Apple product that uses USB charging will charge on a third party charger that has the industry-standard shorted data pins to indicate 500mA charging capability.

One possibility is that the charger is using resistors or an IC to claim a current higher than it can deliver, and then either shutting down under the load, or the voltage sagging enough that the device stops charging.

Finally, when the batteries are extremely low, the initial charge current is kept low (100mA I think? Not sure, it’s been a while since I tested this.) until the device can power up and control charging via the CPU. Perhaps the charger shuts down under the low load?

Anyhow, given that the devices all charge fine on the computer, the problem is almost certainly a defective charger. I strongly advise against using cheap chargers due to safety concerns, so I’d buy a name brand charger (Apple, Anker, Belkin, etc) and destroy the old one. 

[Ed.Kloonk]

Anyhow, given that the devices all charge fine on the computer, the problem is almost certainly a defective charger. I strongly advise against using cheap chargers due to safety concerns, so I’d buy a name brand charger (Apple, Anker, Belkin, etc) and destroy the old one. 

Srs question. Are the name brand ones really safe, though?

I've understood that all these things come out of the same factories. With regard to transformer insulation and HV clearances, some are better than others. Can we rely on Apple and Samsung, name branded (and genuine) USB chargers being safe just on brand name alone?

[Bassman59]

Anyhow, given that the devices all charge fine on the computer, the problem is almost certainly a defective charger. I strongly advise against using cheap chargers due to safety concerns, so I’d buy a name brand charger (Apple, Anker, Belkin, etc) and destroy the old one. 

Srs question. Are the name brand ones really safe, though?

I've understood that all these things come out of the same factories. With regard to transformer insulation and HV clearances, some are better than others. Can we rely on Apple and Samsung, name branded (and genuine) USB chargers being safe just on brand name alone?

The OEMs build to whatever specs are demanded by the customer. Apple says "build it like this," and it's built like this. No-name says, "build like that," and it's built like that. There have been tear-downs of the simple USB power cubes branded as Apple and its clones, and they are different and the Apple-branded product is safer.

(I believe there was a recall of some of the Apple power cubes, for some particular safety reason. Do you think the no-names would care to issue a recall? )

I mean, here in the US the store Harbor Freight likes to claim that the tools they sell are "built in the same factories as the name brands." And that's probably true. But take apart a HF drill and take apart a DeWalt (for example) that costs $50 more, and it's apparent that the latter is better -- better bearings for longer life, for example.

[Syntax Error]

For those playing at home, third party products for Apple devices are certified by the Apple MFi programme. MFi is Made-For-iphone. So you get what you pay for.

Cheap non MFi charger = Dead iPhone

A usefull blog post on "How to identify counterfeit or uncertified Lightning connector accessories": https://support.apple.com/en-gb/HT204566

[BrokenYugo]

Anyhow, given that the devices all charge fine on the computer, the problem is almost certainly a defective charger. I strongly advise against using cheap chargers due to safety concerns, so I’d buy a name brand charger (Apple, Anker, Belkin, etc) and destroy the old one. 

Srs question. Are the name brand ones really safe, though?

I've understood that all these things come out of the same factories. With regard to transformer insulation and HV clearances, some are better than others. Can we rely on Apple and Samsung, name branded (and genuine) USB chargers being safe just on brand name alone?

If they aren't safe they'll get recalled, because the big name brands and retailers, unlike some ebay or Amazon seller operating behind a LLC or straight out of Shenzhen, have a reputation to uphold and actual legal liabilities.

Always buy electrical gear from someplace/one you can sue.  Ebay, anything straight from china, gas stations, and amazon sellers that aren't amazon need not apply.

[tooki]

Anyhow, given that the devices all charge fine on the computer, the problem is almost certainly a defective charger. I strongly advise against using cheap chargers due to safety concerns, so I’d buy a name brand charger (Apple, Anker, Belkin, etc) and destroy the old one. 

Srs question. Are the name brand ones really safe, though?

I've understood that all these things come out of the same factories.

Nah, that’s not really true. No manufacturer that courts the likes of Apple and Samsung would dare risk its reputation by making literally lethal products.

Anyhow, the proof of the pudding is in the eating: teardowns of genuine name brand chargers show enormous differences in construction.

So is a genuine name brand charger safe: absolutely. In fact, the efforts they go to eliminate once-in-a-million failure modes with the potential for human harm are quite surprising. For example, the first generation of Apple’s tiny cube chargers could, in rare cases, come open such that the prongs were left plugged into an outlet, live. Nobody was hurt, but there were a handful of ones that came open. So they recalled millions of them and replaced them with an updated version. And teardowns of the new version basically scream that someone was told “redesign this so that that failure can’t EVER happen, not once in a million, not once in a billion, NEVER.” They certainly wouldn’t entrust this to a power supply company willing to make death traps where only a few microns of lacquer separate the user from mains.

They also recalled a much larger millions of the European one, years later, I forget what for.

With regard to transformer insulation and HV clearances, some are better than others. Can we rely on Apple and Samsung, name branded (and genuine) USB chargers being safe just on brand name alone?

Good question. The answer is: only if bought from an official reseller. The vast majority of Apple and Samsung chargers on eBay, Amazon, etc are counterfeit. But if you buy one directly from Apple, Samsung, a phone carrier store, Best Buy, etc, it’ll be legit. 

[Ed.Kloonk]

Thanks for the replies, guys. I appreciate it.

[GLouie]

This fellow did teardowns of Apple and other USB supplies and found a lot of difference. There is also info on the Apple small cube supply recall, which was for mains blades that could loosen.

http://www.righto.com/2012/05/apple-iphone-charger-teardown-quality.html

http://www.righto.com/2012/10/a-dozen-usb-chargers-in-lab-apple-is.html