PSR650 Charging

[ShellShock]

Possibly this info should go into the MR Wiki, but I don't know how well maintained it is.

Anyway, I'm still looking for a cheapish charger in the UK, preferably one I can get from the high street (in case I have to take it back).

[induna]

Originally Posted by mwheinz

Hoss, I've been a computer engineer for 25 years now. There is no "charging protocol" in USB - at least there is no need for one. Any "protocol" layered on top of simply providing the power levels specified in the USB standards is, by definition, a proprietary hack to keep 3rd party devices from working correctly.

For example, check out this picture. One pin provides +5v, another provides Ground. Current is limited by the spec to 500ma (although it is common for computers to provide more than 500ma for devices that draw a lot of power, like HDs). There is no need for the data pins to get involved when transferring power.

OK so protocol was the wrong word, Hoss.

However if the data pins are being used by the charger the reader will think it is connected to a computer and will not charge properly. That's why users report seeing the 'Connected to Computer' message on their screen when connected to charger that will not work. A charger that only addresses +5v and GND pins will charge the reader fine (I don't know if the data pins are simply left open or if the need to be shorted together). When that type of charger is connected to one of the new readers, the charge light comes on but the the 'Connected to Computer' message does not display and the reader is still usable while charging.

Many third-party USB chargers work fine with the readers. Some do not.

[induna]

Originally Posted by ShellShock

Possibly this info should go into the MR Wiki, but I don't know how well maintained it is.

Anyway, I'm still looking for a cheapish charger in the UK, preferably one I can get from the high street (in case I have to take it back).

Power Traveller (http://powertraveller.com) has a universal travel charger on sale for 9 pounds. These adapters accept a wide variety of tips. If you buy the micro USB tip it will work with your reader. That's what I use. They are located in England.

[ShellShock]

Originally Posted by induna

However if the data pins are being used by the charger the reader will think it is connected to a computer and will not charge properly. That's why users report seeing the 'Connected to Computer' message on their screen when connected to charger that will not work. A charger that only addresses +5v and GND pins will charge the reader fine (I don't know if the data pins are simply left open or if the need to be shorted together). When that type of charger is connected to one of the new readers, the charge light comes on but the the 'Connected to Computer' message does not display and the reader is still usable while charging.

I can't get a refund on the charger I bought, "because it has been used". It has a USB A connector (no cable supplied), with the normal 4 pins. From what you are saying, if I break off the middle two data pins, it should work? I don't know how feasible it is to break them off, but I'm willing to give it a go.

[flyingpostman]

It would be nice to find a compatible USB cable for the 650 as I like to have a cord at home and on the computer at work.

[hahahut]

Originally Posted by chainring

Unless a USB charger goes over the recommended 5 Volts, you're not going to screw up anything. Current (Amps) are like a meal, you can't force it faster than the mouth (device) is willing to take it in. Voltage, however, especially when it's on the higher side, can kill the device. Now, where the mains to USB chargers fail is internally being configured incorrectly. If it's not wired correctly internally, the device (PRS-650, in this case) will see the charger as being a USB port on a computer and limit charging to 500mA. If wired correctly, it will charge at the full rate, say 1A (just an example).

PRS350 User Guide says: Built-in rechargeable battery: 3.7 V DC, 940 mA. So is charger with output 5V and 500mA (or 1A) ok?

[UfeMetti]

Originally Posted by mwheinz

... I've been a computer engineer for 25 years now. There is no "charging protocol" in USB - at least there is no need for one.

Dear Mr. mwheinz,

before posting any assumptions here, taking them for granted just because you have your 25 years experience in computer engineering, you should make sure that you actually do know what you are talking about.

USB Implementors Forum: Approved Class Specification Documents - Battery Charging Specification v.1.1 from April 15th, 2009

If a device wants to draw more than 500mA for charging purposes, the data lines will get involved.

My pleasure!

[andyh2000]

Originally Posted by induna

Power Traveller (http://powertraveller.com) has a universal travel charger on sale for 9 pounds. These adapters accept a wide variety of tips. If you buy the micro USB tip it will work with your reader. That's what I use. They are located in England.

Is this the one - https://powertraveller.com/iwanta/000052/ and it definitely works? I've tried three USB chargers so far and none of them work

Andrew

[induna]

Originally Posted by andyh2000

Is this the one - https://powertraveller.com/iwanta/000052/ and it definitely works? I've tried three USB chargers so far and none of them work

Andrew

Yes. I have the Power Traveler Travel Monkey which comes with this power adapter. With the micro USB tip it charges my 350.

[mwheinz]

Originally Posted by ShellShock

I can't get a refund on the charger I bought, "because it has been used". It has a USB A connector (no cable supplied), with the normal 4 pins. From what you are saying, if I break off the middle two data pins, it should work? I don't know how feasible it is to break them off, but I'm willing to give it a go.

Unfortunately no - if the Sony does require the middle two pins to be shorted together, simply clipping them won't work. You'd have to make a special charging cable by cutting the cable open and shorting the data wires together.

[mwheinz]

(comment deleted)

[Lyn2012]

I'm using a Nexxus UK mobile phone charger from Ebay (seller: thebluetoothcentre) to charge my 350, it seems to work perfectly well and cost £3.99 inc. P&P. I chose this one because it says it is for a Blackberry and somewhere else on these forums I had read that the Blackberry chargers work with the new readers.

[astra]

Originally Posted by Lyn2012

I'm using a Nexxus UK mobile phone charger from Ebay (seller: thebluetoothcentre) to charge my 350, it seems to work perfectly well and cost £3.99 inc. P&P. I chose this one because it says it is for a Blackberry and somewhere else on these forums I had read that the Blackberry chargers work with the new readers.

Is it the same?