Battery test system

[petschi_]

Brief description of the project
I have to build and program a battery test system for school.

What it must be able to do:
-Current and voltage should be logged with timestamp
-Graphical representation of charge and discharge cycles

Cycle:

Load 3 times, unload 3 times -> read characteristic and give rating.

In addition I work with a NI-USB-6008
The question is, how must the LabView program look like, i.e. tricks and tips. I have not so much experience with LabView

[Bob_Schor]

Learn LabVIEW,  Look at the suggested "Learn LabVIEW" links at the beginning of this Forum.  You should have access through your school to some NI Training sessions.  You should also go on the Web and look for NI's DAQmx series of Tutorials -- I especially recommend that you take the one whose name is something like "Learn 10 Functions in NI-DAQmx and Handle 80 Percent of your Data Acquisition Applications".

Attach your USB 6008 to your PC and fire up MAX.  Use MAX to "play" with your Device (make Test Panels, do some A/D, some D/A, some Digital I/O, see how easy it is).  Anything you can do with MAX you can do with DAQmx (to a first approximation).

Bob Schor

[RTSLVU]

My first question is: What size batteries are you testing? (in amp hours)

That makes a big difference in how you test them and the proper equipment to use.

Battery testing is one of my main jobs and I use LabVIEW exclusively.

[petschi_]

Normal rechargeable batteries are used. 12V about 5Ah.
Another battery is a bit bigger. 12V about 9Ah.

Hardware:

-Realize setup
-Load for discharging: about 1-2A should flow
-The battery should not be discharged without current
-Laboratory power supply unit for supply
-NI USB-6008

Target:

You plug in a battery, press the start button, and it will be displayed later,
whether the battery is still good or not.

Questions to be clarified:

-How is it defined whether a battery is still good or not? Limit values?
-How is a distinction made between lead-acid and LiPo batteries?

Would it be possible to contact you privately? so I can show you a picture of the electrical diagram...

[RTSLVU]

---

@petschi_ wrote:

Normal rechargeable batteries are used. 12V about 5Ah.
Another battery is a bit bigger. 12V about 9Ah.

Hardware:

-Realize setup
-Load for discharging: about 1-2A should flow
-The battery should not be discharged without current
-Laboratory power supply unit for supply
-NI USB-6008

Target:

You plug in a battery, press the start button, and it will be displayed later,
whether the battery is still good or not.

Questions to be clarified:

-How is it defined whether a battery is still good or not? Limit values?
-How is a distinction made between lead-acid and LiPo batteries?

Would it be possible to contact you privately? so I can show you a picture of the electrical diagram...

---

That sounds pretty straight forward, were's a few suggestions...

1. Starting with an unknown level of charge 
2. Discharge the battery at a constant current level 
3. During discharge monitor voltage and current
4. Use the current measurement to calculate Amp Hours discharged
5. Halt Discharge at the battery's recommended minimum voltage (10.5 volts is common for 12 volt battery) 
6. Recharge battery using the manufacturers recommended charge profile
   • Lead Acid batteries require a three stage charge profile to be properly charged
   • LiPo? I have not worked with this battery type but I bet they need some special charging considerations since they are Lithium
7. Use current during recharge to calculate Amp Hour restored
8. Goto 2 for several iterations

After a few runs you will know the actual capacity of each individual battery. 

Feel free to private message me.

[Isaac84]

Hello,

Can you share your experience at testing lead acid batteries? Do you have a recommended hardare setup to charge thos 100ah batteries and ten discharge them? I mean do you custom design the charger circuits or buy a programable power supply?

Thank you

[RTSLVU]

---

@Isaac84 wrote:

Hello,

Can you share your experience at testing lead acid batteries? Do you have a recommended hardare setup to charge thos 100ah batteries and ten discharge them? I mean do you custom design the charger circuits or buy a programable power supply?

Thank you

---

We use programmable DC sources to charge and electronic DC loads to discharge.

DC sources we use Agilent, Keysight, and Sorensen in our test systems.

DC loads I prefer TDI Dynaload but have also used Sorensen, NH Research, and Chroma.