OT: Phone charging

There are a number of "fast charging" standards that work by dynamically adjusting the voltage/current output of the charger, perhaps using your Win phone + microsoft charger enables that while the generic just goes fallback.

Is the generic rating 2A in Chinese Amperes?

Another possibility: some cheap charger cables have crazy high resistance.

piglet

I think they are Chinese amps.

One phone has been working flawlessly for a couple of days on a Microsoft charger. One runs for a few hours then craps out on low battery. I put this one on a lab PSU and it was talking a bit over an amp, so I put on a genuine 2A PSU - not a wall wart - and again, it ran for a few hours.

It's warm. I suspect the battery is knackered. It won't work from the charger without the battery in - I wonder if there's some way to defeat this?

Cheers

USB spec is 4.75 - 5.25v. Being at either end can make a big difference to charge speed. Cheap cables can have a lot of R too. And muck in the connect ors can add more. Finally cheapo chargers can put out a right mess - it's a nyone's guess what a phone will do with that.

NT

Yes, and Apple, and Samsung, and...

The usual trick is a passive resistor between D+/D-. It has to be the right value for the brand, of course. 0 ohms is most common, I think, but YMMV.

More advanced controllers actually require a USB negotiation.

TI makes a USB controller that claims to do all the ad hoc "standards", if you're interested...

Tim

My new cell phone has a type-C USB connector so I bought a charger for the car plugging into the cig lighter socket... opps, I mean accessory port. I t has a type-C connector on the end of the cable. What I didn't realize wa s it has a type-C connector on the charger as well, so I can't plug any reg ular USB A connectors into it.

That may be by design because it will vary the output voltage between 5 and 9 volts. If I plugged the wrong device into it damage might result. I do n't know what enables the higher voltage. We'll see if it charges my phone any faster than the laptop USB port.

Rick C.

e car plugging into the cig lighter socket... opps, I mean accessory port. It has a type-C connector on the end of the cable. What I didn't realize was it has a type-C connector on the charger as well, so I can't plug any r egular USB A connectors into it.

nd 9 volts. If I plugged the wrong device into it damage might result. I don't know what enables the higher voltage. We'll see if it charges my pho ne any faster than the laptop USB port.

USB-C can deliver much more power, it can do 5,12,and 20V with 2,3 or 5A

the higher voltages are negotiated over USB so it doesn't happen by acciden t

Thanks, I'll have a look at that. I was charging at >1A from a bench supply, but it was only a two-wire USB cable, so maybe there's a short in the plug.

Cheers

ure the

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a short between D+/D- is the USB standard way of signaling dedicated charge r capable of +1500mA

Clive Arthur wrote in news:pjn532$4ta$1@dont- email.me:

the

All DC PS' supplied power are not alike.

Think PARD.

The purity of the DC source sets most phone charging watchdog circuits to slow charge.

I'd get a USB 3.0 hub as they are fed by a beefier PS and all their ports charge my elements well. One does not require the data link cable even be attached on a powered hub. Mine is an "Insignia" brand. 4 USB ports and fed by a 5V 4.0 A supply, which is likely a far better DC supply than the typical phone charger wall wart. It comes down to ripple figure basically.

Remember the false claims car stereo makers made in the early '70s? Chinese power supply makers are not all alike... at least as far as operational claims go.

Clive Arthur wrote in news:pjnfo9$d4n$1@dont- email.me:

Li Ion batteries have a limited number of charge discharge cycles before total charge voltage and operational efficiency suffers. Put a new battery in OR paralell up two and wire them in OR find a way to wire the charger directly to the phone and fool the phone into taking the fed juice at all times. i.e. simulate a battery at 70% charge all the time.

snipped-for-privacy@decadence.org wrote in news:pjs6u4$1r06$1 @gioia.aioe.org:

note that I refer to lack thereof...

It seems that there is indeed a short.

However, no matter what PSU I use, the phone still craps out with a flat battery after several hours. Running from a bench PSU with a flat phone and with the IP camera app running, the initial current is >1A as the battery charges, this drops to ~600mA after a while. Much later, the phone stops on low battery.

I conclude that once the battery is deemed charged, the external PSU is disconnected. Not unreasonable, I suppose, but not what I want.

It seems the only way would be to supply power direct to the battery terminals.

Cheers

Just too add that the phone does start charging again after it shuts down, but of course the IP camera app has stopped.

Cheers

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it is probably a way for the phone not start to charging every time the battery drops a bit

try unplugging and plugging the charger to start it charging again

what happens if you turn off ther charge voltage for 5 seconds every 20 minutes?

and maybe reduce the voltage (or set the current limit) so that it takes longer to charge.

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arger capable of +1500mA

Is the screen on while running your app? Sometimes i have to turn the scre en way down to keep apps running. Perhaps powering the LCD screen directly ?

You can choose to switch the screen off, which I do.

However, even removing the battery and powering directly from a 4V supply to the battery terminals, it still crashes after some hours. I conclude that the software (sorry, 'app') is s**te. Phones with more memory seem to stay up longer, so who knows, stack problem or somesuch.

I shouldn't be surprised. As an example, there's a Microsoft solitaire game on these phones. All sorts of visual effects, very pretty. But it locks up quite often. The hints are beyond stupid. Style over content.

Cheers

snipped-for-privacy@decadence.org wrote in news:pjs6u4$1r06$1 @gioia.aioe.org:

@dont-

circuits

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USB

Got a new, 7 port USB 3.0 hub with a nice DCPS to feed it.

It was $50 though. (at best buy) Nice hub!