Which battery holder do you recommend to supply power to Arduino Mega which is providing power to a few 5V breakout boards including a wifi board? 3xAA, 4xAA, 6xAA, 3xAAA or 9V? I plan to use Alcaline batteries commonly found in the supermarket. In case the battery holder provides more than 5V, should I connect the plus terminal to Vin of the Mega or buy a Barrel Jack Connector to connect the battery holder to the Mega's Barrel Jack?
To connect to Vin or the barrel jack, the voltage must be a minimum of 7V. Lower voltage will not allow the 5V regulator to work properly. 9V transistor batteries do not have the capacity to run an Arduino for very long (typical PP3 9V capacity is about 300 mA hours). So, of the choices presented, 6AA (9V) is the best (only) choice.
I would use the barrel jack as there is a diode between the jack and the regulator to protect from reverse connection.
A Mega with WiFi shield could draw ~250mA.
Cheap supermarket AA alkalines will have a hard time keeping up with that current.
How long do you expect it to work.
Leo..
Hi,
I use 100's of THESE: on small robots. They run at least 3 to 4 hours on rechargeable NiMh batteries. Alkalines work OK too. So that's 7 to 9 volts which works well.
You can see the battery case HERE:
DISCLAIMER: Mentioned stuff from my own shop...
I need suggestions for two different cases:
-
During the testing phase, I don't mind changing batteries often. So, an hour or two would be OK.
-
After the development, I hope it could run as long as possible. Is a day too much? Perhaps I have to use LIPO instead of Alkalines?
In these two cases, is it better to use such battery holder to supply power for both Arduino Mega and other breakout boards including the wifi breakout or just use such battery holder to supply power for only the wifi breakout?
Barrel jack is not a must as I use breadboard(s) to connect the breakout boards. I could just insert the power and ground wires into the breadboard(s).