I made some modifications to my Battery Test Script.
Removed dropout checks and calculation since my load (DL24P)
has no more dropouts since HKJ improved this in Testcontroller (Thanks HKJ)
Added some options which I liked to have.
So you can check if there is no overload for the load.
See menu.jpg for info.
I also made an version with checking the internal resistance of the battery.
Best is to use an 4-wire connection when your load supports this.
Tested also with an 0.44 ohm resistor in series and it works great.
In Result.jpg you can see how it look.
(BTW used an powersupply and 0.44 ohm resistor in series to test)
Results are dependent on accuracy of the load of coarse,
but Internal Resistance has to do with relative measurement values,
so they should be fairly accurate.
Graph.jpg is an picture made with settings 12V minimum, capacity 2200mAh
and discharge current 1A. Battery simulated by Powersupply with 0.44 ohm
in series. Starting 10 seconds with 0.2C current, 1 second at 1C current.
At this point Internal Resistance is determined.
then further discharge with 1A current.
After shutdown voltage rises a little, is the result of the series resistor.
Internal resistance testing is done by the following rules by IED61960.
According to IEC61960, the DC resistance can be measured as follows:
A DC current step is applied to measure the change in the cell’s voltage.
Battery resistance is defined as the change in voltage over the change
in current when a discharge current of 0.2C is applied for 10s
followed by a discharge current of 1C for 1s.
The DCIR is calculated byformula DCR = (V1-V2)/(I2-I1)
where V1 and I1 are the voltage and current values after the 10s 0.2C discharge just before the current step;
V2 and I2 are the voltage and current values after the 1s 1C discharge.
Rules I have found on
https://www.landtinst.com/what-is-internal-resistance-ir-and-how-to-test-ir/