How I've been testing different batteries.

Endat
 
Posts: 44
Joined: Mon Feb 02, 2015 6:29 pm

How I've been testing different batteries.

Mon Feb 02, 2015 6:57 pm

I made a shell script that measures how long the VoCore has been broadcasting. I have been using it to measure the life of some common 3.7v batteries I have been testing. It's a recursive script that checks to see if the VoCore is broadcasting.. then it just increments the number in count.txt -

And basically all you do is open a terminal, run the script, power on the VoCore, wait for it to say "Online for 0 seconds" and walk away. After the battery dies, the screen will say "OFFLINE! Recorded X seconds of activity!"

Notes/Observations:
- The script is only approximate, there are 2 variables that affect accuracy
- Batteries last longer in the "3.2V ~ 3.5V" pin. When battery dies, the green LED twinkles like a dead star
- When battery is in the "3.5V ~ 6.0V" pin, it goes into a reboot cycle when battery is low.
- This script needs to be run in the terminal on your local Linux machine, NOT the VoCore.
- The script writes to count.txt - so make one in the same directory.
- Batteries last longer when the CPU has a heat sync (I used the one that came with my BananaPi)
- The script does not work in Windows / Mac.

Requirements:
- iw
- grep
- dialog
- write access for count.txt

Before you run count.sh / If you need to reset the count:
Code: Select all
echo -n "0" > count.txt


Making count.sh executable:
Code: Select all
chmod +x count.sh


count.sh
Code: Select all
#!/bin/bash

STATUS=`iw dev wlp13s0 scan | grep VoCore`
COUNT=`cat count.txt`

if [[ -z $STATUS ]] ; then
  dialog --infobox "OFFLINE! Recorded $COUNT seconds of activity!" 3 50
else
  echo -n `expr $(cat count.txt) + 1` > count.txt
  dialog --infobox "Online for $COUNT seconds" 3 30
fi

sleep 1

sh count.sh
Last edited by Endat on Sun Feb 08, 2015 9:49 pm, edited 3 times in total.

tahnok
 
Posts: 1
Joined: Wed Feb 04, 2015 11:45 pm

Re: How I've been testing different batteries.

Wed Feb 04, 2015 11:47 pm

What kind of runtime have you been getting? I'm interested in running my vocore off a small (ish) battery pack

Endat
 
Posts: 44
Joined: Mon Feb 02, 2015 6:29 pm

Re: How I've been testing different batteries.

Thu Feb 05, 2015 6:01 am

tahnok wrote:What kind of runtime have you been getting? I'm interested in running my vocore off a small (ish) battery pack

13 minutes with battery from 3.7v old bluetooth 250mah (old battery, without heat sync) - Taken from Motorola H525
34 minutes with battery from 3.7v old keychin fob spycam 500mAh (old battery, without heat sync)
63 minutes with battery from 3.7v 700mAh from a flip-cam (without heat sync)
118 minutes with battery from 3.7v 700mAh from a flip-cam (with heat sync)

Obviously using a heat sync will increase the battery life. Next I am testing the 3.7v 1,850mAh from my Samsung Galaxy Rugby Pro.. It's a lot larger than the VoCore, but it may last a few hours. I'm using my VoCore out of the box, so I havent updated anything but Im sure there more things to improve efficiency.. like if you don't need a clock
Last edited by Endat on Sun Feb 08, 2015 9:47 pm, edited 1 time in total.

Pyrofer
 
Posts: 61
Joined: Tue Oct 21, 2014 11:35 am

Re: How I've been testing different batteries.

Thu Feb 05, 2015 10:24 am

Correct me if I am wrong, and I hope I am....

if it's 63 minutes from 900mAh or 34 minutes from 500mAh, does that mean it's drawing about 900mA???

That sounds like an awful lot.

Greenwire-Elektronik
 
Posts: 101
Joined: Thu Dec 04, 2014 6:31 am

Re: How I've been testing different batteries.

Thu Feb 05, 2015 11:12 am

Pyrofer - there is the web cam included - i would have appreciated measurements without equiped USB stuff ...
Buy now - breakout board for VoCore to easy adapting your idea!

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Endat
 
Posts: 44
Joined: Mon Feb 02, 2015 6:29 pm

Re: How I've been testing different batteries.

Fri Feb 06, 2015 1:55 am

It used ~700mAh out of the box.. but ~350mAh with the heat sync installed.
Last edited by Endat on Sun Feb 08, 2015 9:38 pm, edited 1 time in total.

Endat
 
Posts: 44
Joined: Mon Feb 02, 2015 6:29 pm

Re: How I've been testing different batteries.

Sat Feb 07, 2015 2:39 am

I disabled SSID broadcasting and did a new run today.. Results:

162 minutes (2.7 hours) w/ 3.7v 700mAh battery (~260mAh)

Total VoCore v1.0 mods:
- Heat Sync installed
- VoCore set as hidden network (http://wiki.openwrt.org/doc/uci/wireless)

These 2 mods added ~100 minutes to the life of the battery.

Also, the SSID was not broadcasting, so I didn't use the original script to measure.. I made a cronjob on the vocore that ran every minute and incremented itself
Last edited by Endat on Sun Feb 08, 2015 9:59 pm, edited 1 time in total.

Endat
 
Posts: 44
Joined: Mon Feb 02, 2015 6:29 pm

Re: How I've been testing different batteries.

Sun Feb 08, 2015 9:57 pm

I just looked at the pictures today, and I was mistaken.. it was not a 900mAh battery, it was a 700mAh battery. Sorry for the confusion :oops:
I updated the previous posts accordingly.

Here is my VoCore with the heat sync:
Image

And during the 162 minute run:
Image

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