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Topic: Charging battery pack through DC jack (Read 1 time) previous topic - next topic

blazen

Right now my Arduino Uno is being powered by a 7.4V Lithium Ion battery pack. The battery pack is connected to a switch. When the switch is turned on, the Arduino is powered through Vin.

I want to be able to charge the battery pack through the DC barrel jack of the Arduino. From my understanding, when powered through the DC jack, the Arduino is powered with regulated 5Vs, and the unregulated voltage can be accessed from Vin.

The problem is that I am using a smart charger for the Lithium Ion Battery and want to be able to safely charge and utilize the charging indicator on the smart charger. But when plugged in, it also powers the Arduino board. Is there a way to bypass powering the Arduino and just access the power through Vin.

Also, can someone further explain the 3 connectors of the DC jack. I saw a post explaining it but can someone give me an example. Thanks.

elandd2011

The DC connector act like a switch.when you plug DC wall adaptor

Grumpy_Mike

Quote
Is there a way to bypass powering the Arduino and just access the power through Vin


Only by hacking the arduino board with a scalpel and soldering iron. See the arduino schematic to find out where to cut tracks.

blazen


Quote
Is there a way to bypass powering the Arduino and just access the power through Vin


Only by hacking the arduino board with a scalpel and soldering iron. See the arduino schematic to find out where to cut tracks.


If I just disconnect the power pin from the board and then connect that directly to the battery do you think that will work?

Grumpy_Mike

Not sure I understand that. If you disconnect the power pin on the DC jack you might as well not plug it in, in the first place.

blazen

I'm using an arduino enclosure with the circuity and battery connected in the enclosure. I want to be able to charge the battery by plugging the charger through the DC jack on the board rather than installing another DC jack.

floresta

#6
Apr 26, 2011, 08:09 pm Last Edit: Apr 26, 2011, 08:13 pm by floresta Reason: 1
If this Arduino is part of a finished project rather than one you use every day and if it does not incorporate a shield then you might want to consider using a Bare-Bones Board from ModernDevice (http://shop.moderndevice.com/products/bbb-kit).  This board does not have the automatic power switching of the Arduino, instead the power connections are manipulated by means of jumpers.  It is the availability of those jumpers that makes what you want to do very simple.  Use the diagram (in the BBB instruction sheet) labeled "Power to BBB from +6 -12 volt unregulated breadboard rail".  Use a switch instead of a jumper for the lower (EXT/USB) header and you can turn the processor on and off with that switch.  You would then power the board from your batteries via the 'Breadboard power rail pins' and connect your charger via the Power Jack.   You would just have to swap chips between the BBB and your Arduino and you have your project running on the BBB and you have your Arduino back to play with.

Don

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