Can use two 3.7V AA battery?

by tony18183 on Thu Apr 19, 2012 8:08 am

Is it okay to use two 3.7V AA battery to replace two 1.5V AA battery?

brighter LED?
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Re: Can use two 3.7V AA battery?

by adafruit_support_bill on Thu Apr 19, 2012 8:12 am

Two 3.7v cells is way too much voltage. You will burn out the LEDs if you don't fry the processor first.
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Re: Can use two 3.7V AA battery?

by tony18183 on Thu Apr 19, 2012 9:29 am

what is the maximum voltage can take without getting the LEDs or processor fry?
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Re: Can use two 3.7V AA battery?

by adafruit_support_bill on Thu Apr 19, 2012 10:01 am

The processor is 5.5v max. For the LEDs, you need to worry about current. The current going to the leds is controlled partly by the battery voltage and partly be the resistor arrays RN1-RN8. The LEDs are rated for 20mA each.

Details on driving LEDs are here: http://www.ladyada.net/learn/arduino/LEDs.html
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