Discussion in 'General Electronics Chat' started by jeevi, Aug 1, 2013.

1. ### jeevi Thread Starter New Member

Jun 17, 2013
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0
I am using a rechargeable NiMH battery (300mAh,4.8V) to supply the WSN mote. The battery gets an average energy of 300J per day from a solar cell. Assuming that the mote consumes 0.163928mAh per day. Can anyone please say me the life of the mote and how to calculate it?

2. ### bountyhunter Well-Known Member

Sep 7, 2009
2,498
507
The Watt is defined as a Joule-per-second. I think you need more info to calculate the problem.

The battery: 300mAh,4.8V is about 1.5 Watt-hour.

3. ### #12 Expert

Nov 30, 2010
16,655
7,293
What is a "mote"?
What is a "WSN mote"?

4. ### wayneh Expert

Sep 9, 2010
12,361
3,220
Are you sure it's not 0.163929?

5. ### crutschow Expert

Mar 14, 2008
13,462
3,353
300mAh at 4.8V is 0.3Ah x 4.8V = 1.44Wh. 300J is 300 Watt-sec or 300/60 = 5 Wh. Thus the battery is fully charged each day.

0.163928mAh per day is a very small current (0.163928mAh / 24 = 6.8μA. Should it be 0.163928Ah per day which would give 6.8mA? That would give a daily energy consumption of .164Ah * 4.8V = .787Wh. On that basis the battery would last 1.44 / .787 = 1.8 days without charging.

6. ### jeevi Thread Starter New Member

Jun 17, 2013
4
0
both mote and WSN mote are same...
at very low duty cycle ratio, there is possibility of such reduced current consumption.

If not consider that to be 46.117mAh per day, and help me..
thanks crutschow,
can u please, say the procedure to calculate lifetime with recharging the battery..

Last edited: Aug 2, 2013

Sep 9, 2010
12,361
3,220

8. ### #12 Expert

Nov 30, 2010
16,655
7,293
Same as what? Same as each other? That doesn't tell me anything.

9. ### jeevi Thread Starter New Member

Jun 17, 2013
4
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yes the possible recharge cycles

10. ### Kermit2 AAC Fanatic!

Feb 5, 2010
3,837
961
http://en.wikipedia.org/wiki/Wireless_sensor_network

NiMH battery chemistry is not going to provide a very long useful recharge life for the units(several months before degradation lowers capacity below useful limits).

If your power requirements can be lowered even more than what you have now, a super capacitor may be able to supply the load during dark periods and it would have a much much better recharge lifetime (multiple years)than the NiMH batteries.

11. ### jeevi Thread Starter New Member

Jun 17, 2013
4
0
fine, i'll check that option too