We have run some battery tests with our routing protocol and for the first time have used some mica2dots.
The results are fairly devastating. Some Motes never worked at all. After investigating the problem we found that the current draw was too high and that the voltage of the coin cell dropped below the brownout threshold. The motes just resetted every time we wanted to send a packet. So we had to solder a capacitator to + and ground to make them work at all. Still with the supplied button cells (Panasonic CR 2654) a mote dies after two to three hours of continuous operation. At first we couldn't point our finger to the problem since we only draw abour 20mA of current and therefore thought that a coin cell should last for at least a day. After downloading the data sheet for the coin cell however we had to realize that the coin cells are only specified for 0,2 mA continuous draw. 20 mA is 100 times more than that so no wonder that the batteries die after such a short time. One would have to set the duty cycle of a mica2dot to 1 percent (assuming 20 mA current consumption) to get the full 500 mAh of the coin cell. Are we doing anything wrong or are these running times accurate? How comes that some motes draw su much current that they are not working at all? I still think that we might have made an error since I couldn't find anything related to battery running times or problems with the motes on the mailing lists or at crossbow. Christian
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