Kensington 4-port Charger and Treo Pro

[jbinmn]

Does anyone have experience using 3rd party chargers with the Treo Pro or HTC devices in general?

I've purchased a kensington 4-port USB wall charger. It's an interesting concept which allows you to plug in up to 4 USB cables (iPods, iPhones, Treo Pro) and only use one outlet. A neat trick when you have multiple phones and devices in your family.

My problem is that the kensington won't charge the Treo Pro. When I plug it in, the LCD lights up, but the charge indicator does not appear nor does the tone sound that it has been plugged in. Note, as far as I can tell the Treo Pro charger outputs 5v DC exactly the same as the Kensington charger.

I've read several posts that lead me to believe that HTC does something to their devices that only allow certain chargers to work or that their USB cables have a certain pin-out that allows them to charge. Anyone have any advice?

Thanks!

[my2se]

Well, I got my wall charger and car charger from Officemax. The charger brand is "Just Wireless". Both are working fine for me. Before, I tried to use the sync cable to plug the regular USB power adapter for wall or car charger, some work, some don't. It seems Palm modified the micro-usb cable...
So my suggestion, if you are looking for charger for Treo Pro, you should look for compable with Moto R9 (which using micro-usb plug, too) I used to have one Moto charger, It worked in my Treo Pro!

[frause]

My problem is that the kensington won't charge the Treo Pro. When I plug it in, the LCD lights up, but the charge indicator does not appear nor does the tone sound that it has been plugged in. Note, as far as I can tell the Treo Pro charger outputs 5v DC exactly the same as the Kensington charger.

I've read several posts that lead me to believe that HTC does something to their devices that only allow certain chargers to work or that their USB cables have a certain pin-out that allows them to charge. Anyone have any advice?


There's really nothing "special" going on here. It's all in the USB spec. http://http://en.wikipedia.org/wiki/USB#Power (http://en.wikipedia.org/wiki/USB#Power)
That said, there are few other devices that demand a dedicated charger (or a communicating host), so in that sense it is special.

The problem being that the TP won't draw more power than agreed upon with the host (or in this case the carger). And since your charger doesn't tell the Treo that is has power to spare, the Treo trying being a good little device won't start charging.

Now, for the charger to tell the Treo that it is, in fact, a dedicated charger and "go ahead, draw as much power as you want up to 1.8A" it would only have to short its data pins.

Now that is something YOU could do to get the charger to work with your Treo. Either open the charger and solder the data pins (the two middle ones in a normal sized usb socket). Or if you can't for some reason, slice a micro-usb cable open and short the two data (usually the thinnest (green/white maybe)) wires inside.

[alexbergh]

I got a couple of desktop chargers from ebay for about £8 each. Work fine.

[HyperZ]

There's really nothing "special" going on here. It's all in the USB spec. http://http://en.wikipedia.org/wiki/USB#Power (http://en.wikipedia.org/wiki/USB#Power)
That said, there are few other devices that demand a dedicated charger (or a communicating host), so in that sense it is special.

The problem being that the TP won't draw more power than agreed upon with the host (or in this case the carger). And since your charger doesn't tell the Treo that is has power to spare, the Treo trying being a good little device won't start charging.

Now, for the charger to tell the Treo that it is, in fact, a dedicated charger and "go ahead, draw as much power as you want up to 1.8A" it would only have to short its data pins.

Now that is something YOU could do to get the charger to work with your Treo. Either open the charger and solder the data pins (the two middle ones in a normal sized usb socket). Or if you can't for some reason, slice a micro-usb cable open and short the two data (usually the thinnest (green/white maybe)) wires inside.


Hi!

Yep i just bought two kensington 4 port chargers and looks like it doesnt charge the TP :(

Im about to buy a microusb cable to do the trick you suggested, (i cant seem to open the Kensington 4 port!), any reference websites you could suggest that could explain abit more about the shorting of the data wires inside? Just like to read up abit more before the cable arrives ;)

Thanks!

[zamiv]

Thank you for the details. I was able to get two car chargers to work with Palm cables after opening them up and shorting the middle pins with a dab of solder. I opened up a non-Palm cable and discovered only two wires, red and white, and no surprise: it did not work even with the "fixed" adapters. So you need to have pins shorted, and a cable that can return the short to the Treo from the adapter, or if you have a cable with all leads inside you could short the two wires instead and leave the adapter alone. However, if you only have two wires inside the cable you would have to short inside the micro plug, which is a little cramped to work in. If you have only two wires in your cable (hard to tell really without cutting it open; too small to get a continuity probe in there), and/or an adapter without the pins shorted, the Treo will not pull current and charge itself.

[dsa.tcp]

The Wikipedia USB Spec referenced by frause above says in part:

" A Dedicated Charging Port can supply a maximum of 1.8*A of current at 5.25*V. A portable device can draw up to 1.8*A from a Dedicated Charging Port. The Dedicated Charging Port shorts the D+ and D- pins with a resistance of at most 200O. The short disables data transfer, but allows devices to detect the Dedicated Charging Port and allows very simple, high current chargers to be manufactured."

An interpretation of the reported observations and this spec is that a charger can communicte to the device under charge the maximum current the charger is able to supply. This communication occurs by the charger either "shorting" the data pins or not. Non-shorted data pins indicates that the charger is capable of at most 500 mA. Its possible that the Treo Pro(TP) is smart enough to know it should conserve power when being charged from a low current charger. One way for the TP to conserve power would be to not power the LED on the TP if there is only 500 mA available for charging.

NOTE THAT IF THIS INTERPRETATION IS TRUE THEN IT IS ACTUALLY DISADVANTAGEOUS TO ARTIFICIALLY SHORT THE DATA PINS.