How To reduce Arduino Power consumption?

I copied this project and am using a Arduino uno Atmega 328 with a RTC, micro Sd card, And a DHT22

The problem I'm having is that i'm using a 9V battery to power it and its dying within 6 hour. How do I make it so that the battery will last for weeks?

Can you please show me how to reduce the power consumption of this proiect?

These are some websites I have looked at to solve the problem:

Use AA batteries and not PP3's. Rechargeable ones are most cost effective and use a 12v pack not 9v.


Need to run a standalone design & drop the power dissipating parts to start:
9V to 5V regulator
5V to 3.3V regulator
power on LED
autopower select comparator
USB/Serial interface

Try using a 3.3v promini running from 3x AA batteries, or a 3.7-4.2V LiPo and ditch the 9v battery.

how would you make the Arduino uno sleep in between the temp./humidity readings? I have heard it can be done but don’t know how

See my link above.

Make a standalone arduino and dont use voltage regulator (LM7805). Else you can feed 4.5V with 3 x AA. You can switch to 3.3V and 8mhz that will be even less consuming.

Using sleep helps a lot too.

what about using 1.5v D batteries, or 1.5v C batteries?

...Can it be done?, i'm assuming it can as long as its close to 5v.

what about using 1.5v D batteries, or 1.5v C batteries?

Use a silicon diode with 4, 1.5 V batteries.

4 X 1.5V = 6V - .7V = 5.3V