BlackBerry charger doesn't charge Motorola V3xx Razr

Hi. I have a Motorola V3xx Razr phone. It has a USB Mini-B jack for chargin g.

formatting link

I tried charging it with a BlackBerry wall wart. I can't make out the model number of the wall wart due to the small size of the type. I can come up w ith that later. When I plugged the BlackBerry wall wart into the phone, the phone came on, but the battery did not charge.

I tried another wall wart. It's a Verizon wireless model PW-1BGT charger, w hich can source 800 mA at 5.0 V. When I plugged it into the phone, the phon e's "charging battery" screen lit up. It did charge the phone's battery pac k. When I disconnected it, the phone turned itself off.

The pinout chart at Wikipedia makes me think that there is difference in th e way pin 4 is wired, rather than an inability of the BlackBerry charger to source sufficient current.

formatting link

Am I right?

Thanks.

Reply to
Beloved Leader
Loading thread data ...

Perhaps, but my guess is that the problem is elsewhere.

Read down a bit further to the "Charging ports and accessory charging adapters" section.

My guess is that the Razr phone has a different method/protocol to determine the amount of charging current available from the "upstream" device than the BlackBerry wall wart. As a result, the Razr isn't able to identify the wart as a source that can supply the amount of current that the Razr's charging circuitry requires.

A USB-connected device is supposed to behave as a "low power" device (drawing no more than one 100 mA unit load) unless/until it successfully negotiates with the upstream device and is granted permission to draw more power, or unless it successfully identifies the upstream device as a dumb "dedicated charger". My guess is that neither of these things happens when you connect to the BlackBerry wart, and so the Razr is "playing by the rules" and is drawing only the minimum amount of power.

Reply to
David Platt

is wired, rather than an inability of the BlackBerry charger to source sufficient current.

Solder pin 4 to pin 1, it will charge then.

Reply to
Congoleum Breckenridge

of the type. I can come up with that later.

== == == ==

Thanks for the answers.

I managed to make out the model number of the BlackBerry wall wart. It is P SM05R-050CHW (R) P {though I think the (R) and P are not part of the model number.} The RIM part number is ASY-07559-001. It is able to source 500 mA at 5V.

Hmm: someone's trying to sell one at Amazon:

formatting link

0G3AO2

And here too:

formatting link

They call it a charger. I guess it has enough output for the models of Blac kBerry devices listed, but not enough to charge the V3xx Razr. Either that, or I wouldn't have to solder pins 1 and 4 for the device to charge one of the specified BlackBerrys, as one respondent said would make it charge the Razr.

I left the Razr at home, but a search shows that it uses a BZ60 battery, sa id by at least one seller to be good for 900mAh.

Thank you again.

Reply to
Beloved Leader

Thanks. I found that thread, from last September, "USB chargers, anyone?"

formatting link
$20ports/sci.electronics.repair/nTjHvzmHZtU/xO_39aTypQwJ

Reply to
Beloved Leader

I think so... There appears to be a 200k resistor /inside/ the motorola charger cable moulded mini USB plug:-

formatting link

Reply to
Geo

== == == ==

Thanks for the link. The page at Pinoutsguide seems not to use the same nomenclature for number pins as the page at Wikipedia. It's easy enough to figure out what they mean.

My takeaway from this is that universal chargers are not as universal as they seem.

Thanks again for everyone who has helped me.

Reply to
Beloved Leader

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.