pet monster Posted April 30, 2010 Report Share Posted April 30, 2010 I'm very new to this so be gentle.I have a small fan that runs on 1 AAA battery and, because the case is difficult to get into, I'm attempting to use a rechargeable AAA battery in it's place attached to a USB wire to charge it with a male USB connector set outside of the fan unit.So far I have soldered a male mini USB connector to a wire. Positive (pin1) and negative (pin 5). It tested fine showing power through the connector.Question(s):If I attach a rechargeable AAA battery to a USB port, what'll happen?Do I need to put some sort of charging gateway between the battery and the USB wire?I can take pics if that helps! Quote Link to comment Share on other sites More sharing options...
JamesUWF Posted April 30, 2010 Report Share Posted April 30, 2010 Might be easier just to use a thermal lens with your mask, if you haven't already. James Quote Link to comment Share on other sites More sharing options...
pet monster Posted April 30, 2010 Author Report Share Posted April 30, 2010 Thanks JamesUWF. Already did that but once in a while, it still fogs up. I run a lot and usually for play 8 hours at a stretch.Not to mention that my overactive mind wont let this go. :-[ Quote Link to comment Share on other sites More sharing options...
pet monster Posted May 1, 2010 Author Report Share Posted May 1, 2010 * Update*Attaching a AAA battery through a wire to a USB port (as discribed above) is safe however, it just drains the battery and shuts down the USB port temporarily and reports, "Power surge on line".Still need help with some sort of powering gateway. How does a battery know to charge instead of supply energy? Quote Link to comment Share on other sites More sharing options...
Hero999 Posted May 2, 2010 Report Share Posted May 2, 2010 A battery will charge when it's connected to a higher voltage than the battery terminals and discharge when it's connected to a lower voltage.I would've thought the USB current limit would have been exceeded causing the USB to shut down so maybe the battery discharged into the USB port? Quote Link to comment Share on other sites More sharing options...
JamesUWF Posted May 7, 2010 Report Share Posted May 7, 2010 Pet Monster,Have you taken a look inside your computer to see if there are any devices that regulate current to USB ports? Maybe something like a TPS2032D, or similar? If so, there is a chance it will have an OC output that is asserted when an overcurrent or thermal shut down occurs. You might monitor that output to give you some idea what is going on when you connect your battery to USB power. I'm wondering if (and how) the battery is discharging through that device when it is in shut down mode. James Quote Link to comment Share on other sites More sharing options...
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