need idea on testing based 1. Battery Voltage/Current as it discharges and system run time.

[rvillarr]

need idea on testing based Battery Voltage/Current as it discharges and system run time what type of measurement system and able to get data?

[Matt_L]

The simplest way to do this would be with any of our USB data acquisition products, which you can find here: http://www.ni.com/data-acquisition/usb/.

You can filter by the analog input measurement type, range, etc. until you find a suitable module.  You likely won't need a very high sampling rate if this is the only type of measurement you plan to take.

As far as setting up this system, there are tons of tutorials and examples for getting started with this.  The guide here should give you all you need to get started with taking these measurements:http://www.ni.com/white-paper/5468/en.

Also, be sure to take a look through the Example Finder in LabVIEW, specifically under Hardware Input and Output -> DAQmx, for more specific examples on acquiring and logging your data.

[rvillarr]

Hello Matt, thanks for the fast response. All I want to do is monitor a fully charge battery pack and use UUT without charging and monitor, how much time it takes discharge. This would work in collecting time respionse, what current conditions as well voltages..?

[mostafabayern]

Hello,

It deponds on how accurate you want your results to be, if you need them very accurate i believe it is complicated because of battery aging (which means the capacity of the battery decreases by time, in order to update the capacity values it is kinda complicated.) however neglecting the aging factor, you need fast sampling rate (battery used in cars for example a measurement each 5 to 10 ms).

How to know the actualy capacity of your battery?

1- read first value from state of charge vs open circuit voltage curve (you can get it easily from manufactor).

2- as your battery starts running you can not read from the curve any more as a result:

the new state of chage= the old state of charge (5 mili seconds ago) + 100*integral of( new current measurement by time)/ the whole capacity of the battery

hope i was helpful