Arduino project battery question - multiple 5v sensors w/SD shield

Using Arduino General Electronics
#1

I am working on a project to send an Arduino up to high atmosphere with a weather balloon. I just got the board and all of the sensors working (powered by USB) and am starting the process of determining the battery requirements for the whole thing.
I tried using a 9 volt battery and while it powered the Arduino for about 15 hours, there was no data from the sensors written to the file on my SD card. The sensor data writes just fine when attached to USB power.

Here are the sensors I am using (they are all using 5V power):
(2) Tmp36 Datasheet
ASDX pressure sensor Datasheet
Adafruit digital UV/IR sensor Datasheet
SainSmart Micro SD Storage Board SPI For Arduino (Datasheet not available - used these directions to install and program

I am still working on attaching these sensors but they are not currently part of my sketch. If anyone has any info or experience with these sensors, I would appreciate any info you might have.
DE-ACCM6G Accelerometer Datasheet
HIH4031 humidity sensor Datasheet With this breakout board Datasheet

I’ve attached our sketch if you would like to take a look.

TL;DR - Need help determining what kind of battery for my project - sensors are all 5V and 9V battery powers but writes no data to SD card.

Thank you all in advance!

TestSensorToDataFile.ino (5.31 KB)

#2

I think your choice of battery might need reviewing. Is that a 9V battery like those in smoke detectors? If so, they have a very low current capacity, probably not suited to your application.
Have you monitored the battery voltage at all?

LiPo batteries are probably the best choice for a project like this. They have the highest energy density, so a very small 7.2V LiPo would do the job.
A quick, rough tally of the current usage of your sensors yields about 12mA continuous, plus a few mA for the Arduino and it's onboard regulator etc, so virtually any 7.2V LiPo should do. (Anything but one of those 9V batteries. :smiley: )

#3

I have not monitored voltage for the whole project. I have voltage values for each sensor I'm using so far. Is it as simple as adding those average values to get a total voltage? Or am I missing something important?

#4

ASENDprojectCAC:
I have not monitored voltage for the whole project. I have voltage values for each sensor I'm using so far. Is it as simple as adding those average values to get a total voltage? Or am I missing something important?

I just edited my post. You don't want to add the voltages - you add the current consumption of the devices, which I did (roughly).

#5