Battery testing Depth of Discharge using Agilent 6060B electronic load

[JettZ]

I am trying to sum up the data from my program txt file "current * time" of each row to calculate the depth of discharge? May I ask some assistance, Thank you so much. I am a labVIEW beginner doing battery management project. 

[RTSLVU]

Having done battery charge/discharge cycle testing here's a couple things I learned....

The most accurate way to get Amp Hours is to use a Wattmeter that has an Integrator function that will count Watt/Amp hours for you

But since it is a constant current discharge you can simply accumulate the current over time

Ah Discharge = Ah Discharge + (Ibatt*t)
t = Measuring interval in hours (seconds/3600)

Calculating the recharge Ah with this method is less accurate as batteries are usually charged in constant current mode for most of the charge but the last %20 or so is in constant voltage mode. So the less time between measurement intervals the more accurate you recharge Ah will be.

[LVNinja]

What have you done so far ? 

[RTSLVU]

I forgot to add, I didn't comment on your code because honestly I don't understand what you are doing with all those Queues and Notifiers. nor do I have the time to figure it out.

[JettZ]

so far I had run the discharge test for 22Ah lead acid battery  using constant current mode. I recorded all the data using queue machine and extract it to the table in labview, and store in txt file. I wanna try if can use those data in txt file to calculate the DoD and display it on screen. My plan is to use the constant discharge current * the discharge time (s) over the battery capacity * 3600 then multiply it by 100% to get DoD. The current problem I face is dk how to extract the total discharge time out. 

[RTSLVU]

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@JettZ wrote:

so far I had run the discharge test for 22Ah lead acid battery  using constant current mode. I recorded all the data using queue machine and extract it to the table in labview, and store in txt file. I wanna try if can use those data in txt file to calculate the DoD and display it on screen. My plan is to use the constant discharge current * the discharge time (s) over the battery capacity * 3600 then multiply it by 100% to get DoD. The current problem I face is dk how to extract the total discharge time out. 

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So you are going to write your data to a file then read the file for discharge time? 

Well you can do some math directly on timestamps as long as they are in the right format when you read them back from your file.

Discharge time = End time - Start time 

In my testing the batteries were for a UPS and one of the things that people want to know is battery runtime under various loading conditions. I would accumulate this during the test just like Ah discharged. 

Runtime(Minutes) = Runtime+t
t = (Time.This Scan - Time.Previous Scan)/60

If you are taking measurements at regular intervals, just add them up. My program the measuring interval was user adjustable so I had to do the math every time.