Hi all,
I am working for a pir motion sensor with esp 8266 wifi module and the circuit is as follows, i need to build the circuit with low power consumption ,and the circuit should be in very small size using button battery ,with a lifespan about 1 year.
Note: pls avoid the leds in the below image, and the battery is showed just for reference, i need to use button battery.

I think the pir sensor take 200 ma and esp 8266 takes 170 ma , circuit is to be work in a 5 v button battery.
Can anybody suggest the battery need to use to work for 1 year..

Regards,
Ajin nadh

 

Hi all,
I am working for a pir motion sensor with esp 8266 wifi module and the circuit is as follows, i need to build the circuit with low power consumption ,and the circuit should be in very small size using button battery ,with a lifespan about 1 year.
Note: pls avoid the leds in the below image, and the battery is showed just for reference, i need to use button battery.
View attachment 120431
I think the pir sensor take 200 ma and esp 8266 takes 170 ma , circuit is to be work in a 5 v button battery.
Can anybody suggest the battery need to use to work for 1 year..

Regards,
Ajin nadh

370 mA for a 24hx365d application? That is about 3000 Amp-hours, you'll need about 6 standard lead-acid car batteries. But, since they go dead by standing without use in 6 to 8 months, I would go with AMG style batteries.

 

370 mA for a 24hx365d application? That is about 3000 Amp-hours, you'll need about 6 standard lead-acid car batteries. But, since they go dead by standing without use in 6 to 8 months, I would go with AMG style batteries.

How can i reduces the power consumption...

 

How can i reduces the power consumption...

Remote-entry key fobs and garage opener transmitters work on button cell batteries because they are only in for a fraction of a second every day. I don't know of any wireless transmitters that can stay on for an extended period with a button cell (or small lithium pack). Trying to check this type of sensor for a few microseconds every second doesn't work either because a PIR won't work that way - it has to know the current state in order to detect a next state (motion). And, as far as I know, PIR sensors don't come in an "ultra-low power" version.

 

I think you may be incorrect about the current levels- PIR sensors are very low power.
200 ma sounds way too high.

 

Hi,
While checking some websites i found that the pir along with the wifi module at sleep mode take less than 30 ma.
by making some changes in the board and code(sleep mode).then which type of button battery i can use

 

Hi,
While checking some websites i found that the pir along with the wifi module at sleep mode take less than 30 ma.
by making some changes in the board and code(sleep mode).then which type of button battery i can use

Then you are down to 262 amp*hours of power. That is, 262000 mA*hours or about 175 pairs of AA batteries in a year - assuming 3v works for your PIR.

 

Then you are down to 262 amp*hours of power. That is, 262000 mA*hours or about 175 pairs of AA batteries in a year - assuming 3v works for your PIR.

Sir,
is my below calculation is correct..?


Total Current Consumption:- 30 mA

Voltage:- 3.3V

If want it to run for 1 hours

C = 0.03 Amps * 1 hours = .37 amp hours

For 80% power consumption

c=.03/.80= 0.037AH

Rate of discharge considerations

c=.46/.5=.075 Ah

 

30 mA = 0.030 amps

For one hour of operation, 0.030A for 1-hour = 0.030 A*hour

For one year of operation, (0.030A*hour) X (24 hr/day) X (365 day/year) = 262 A*hours


An AA-sized battery (1.5V) is 1.5 A*hour. You wanted about three volts so you need two batteries in series. So it takes two batteries to make the 1.5A*hour at 3V.

You'll have to check the C-rating of any battery you want. I try to limit a AA battery discharge rate to 0.5 amps so that is way more than you need.

My point is that a button battery is out of the question unless you put a bucket-full of button batteries in parallel at the beginning of each year.

 

30 mA = 0.030 amps

For one hour of operation, 0.030A for 1-hour = 0.030 A*hour

For one year of operation, (0.030A*hour) X (24 hr/day) X (365 day/year) = 262 A*hours


An AA-sized battery (1.5V) is 1.5 A*hour. You wanted about three volts so you need two batteries in series. So it takes two batteries to make the 1.5A*hour at 3V.

You'll have to check the C-rating of any battery you want. I try to limit a AA battery discharge rate to 0.5 amps so that is way more than you need.

My point is that a button battery is out of the question unless you put a bucket-full of button batteries in parallel at the beginning of each year.

This means two button batteries will last for 50 hours, am i right?

 

This means two button batteries will last for 50 hours, am i right?

A cr2032 has a 225mAH rating and two in parallel will be 450 mAh.

450mAh / 30 mA = 15 hours.

 

The solution to your problem, if there is a solution, depends on how you control the PIR detector and the EST8266. The ESP8266 chip itself only draws 10 uA in deep standby mode. You might be able to only have power on the PIR sensor look enough to peek at the sensor's output. If you can get that far then it is mostly a matter of keeping the duty cycle of those loads very small and then you attention needs to turn to the controller and how to keep it asleep most of the time.

If you bought one of those popular ESP8266 modules you will notice that it has its own CPU with a little bit of general purpose I/O brought out onpins and maybe you can control everything with that.