USB battery charging (500 Views)
Posts: 20
Registered: ‎01-07-2003
Message 1 of 7 (500 Views)
Accepted Solution

USB battery charging

Hi folks

Why doesn't my 3970 charge while connected to my PC with a USB cable?

Regards to all

Honored Contributor
Posts: 4,200
Registered: ‎10-11-2002
Message 2 of 7 (500 Views)

Re: USB battery charging

If you have a sync/charge cable you should have no problem... What brand and type of cable are you using? Belkin has a switch on the cable that has to be in the "charge" OR "sync" position. If you are syncing it will not charge (and will not sync while charging)..
Honored Contributor
Posts: 1,683
Registered: ‎03-18-2002
Message 3 of 7 (500 Views)

Re: USB battery charging

USB is not designed for devices that drain a lot of power. Some cables are setup not to provide power to the devices. Others can, but some systems/devices do not work when power is required. This was a big problem with USB 1.0 ports.
Posts: 21
Registered: ‎01-03-2003
Message 4 of 7 (500 Views)

Re: USB battery charging

I have a belkin cable that does not have a switch. I think it uses 2 wires for charging and 2 wires for sync. My understanding is that the amount of current supplied from a USB port to the ipaq battery is much less than the current from your AC adapter. So its enough current to slowly charge the battery if the unit is switched off, but it is simply not enough current to power the ipaq AND charge the battery.
Regular Advisor
Posts: 89
Registered: ‎01-13-2003
Message 5 of 7 (500 Views)

Re: USB battery charging

You might want to check out my page:

It describes how I modified my cradle to charge from USB.

USB can charge IPAQ3970+GSM/GPRS wireless pack simultaniously
- just a little slower than the power dapter.
Posts: 20
Registered: ‎01-07-2003
Message 6 of 7 (500 Views)

Re: USB battery charging

Hi everyone

Thanks for all of this info. I'm now charging successfully!

Best regards

Frequent Advisor
Posts: 34
Registered: ‎11-13-2002
Message 7 of 7 (500 Views)

Re: USB battery charging

Also, it depends where the other end of the USB cord is plugged into. It sounds stupid, but i had one that wouldnt charge with my new laptop, but it would charge fine when i plugged it into the wall. I was going from battery to battery. [duh] Anyways, if your going from a wall outlet.... *shrug*

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