hjr

Status Update
At the end of a couple of weeks of testing various combinations of ICC versions on a Pi3 and a Pi2, with Debian Buster Operating system and with the Debian Stretch Operation system, I figured that the culprit was a SD Card with some sort of file corruption.
On creating a new SD Card from the latest Pi4 image (with the Buster OS) to test on a Pi3, ICC immediately started to run smooth without any freezing problems. When testing the same on a Pi2, the same result as with the Pi3, no freezing. However the Pi2 struggled with the screen refresh rates of ICC on Buster OS. Done the same with the new SD Card but with Stretch OS on the Pi2, also no freezing so far, but with better screen refresh rates of ICC.
As part of the tests, I replaced the power supply on the Pi2 with the power supply of the Pi3 (5.1V 3.0A), and then realize that the Pi2 was under powered. According the Raspberry Pi forums, an under powered Pi can cause SD Card corruption.  On a Pi2, the red LED must be constant On, this is showing that the Pi2 is receiving sufficient power. If it flickers or is Off then the Pi2 is under powered. This was the case with the Pi2 before changing the power supply.
My only conclusion, at the moment, is that there is file corruption on the old SD Card of the Pi2 which caused the newer versions of ICC to freeze. The file corruption was caused by an under powered Pi2.
So far, the current run time of ICC V2.9996 on a new SD Card with Stretch OS on a Pi2 with a Pi3 power supply is approaching 70:00 with out any freezing problems.

Status Update
At the end of a couple of weeks of testing various combinations of ICC versions on a Pi3 and a Pi2, with Debian Buster Operating system and with the Debian Stretch Operation system, I figured that the culprit was a SD Card with some sort of file corruption.
On creating a new SD Card from the latest Pi4 image (with the Buster OS) to test on a Pi3, ICC immediately started to run smooth without any freezing problems. When testing the same on a Pi2, the same result as with the Pi3, no freezing. However the Pi2 struggled with the screen refresh rates of ICC on Buster OS. Done the same with the new SD Card but with Stretch OS on the Pi2, also no freezing so far, but with better screen refresh rates of ICC.
As part of the tests, I replaced the power supply on the Pi2 with the power supply of the Pi3 (5.1V 3.0A), and then realize that the Pi2 was under powered. According the Raspberry Pi forums, an under powered Pi can cause SD Card corruption.  On a Pi2, the red LED must be constant On, this is showing that the Pi2 is receiving sufficient power. If it flickers or is Off then the Pi2 is under powered. This was the case with the Pi2 before changing the power supply.
My only conclusion, at the moment, is that there is file corruption on the old SD Card of the Pi2 which caused the newer versions of ICC to freeze. The file corruption was caused by an under powered Pi2.
So far, the current run time of ICC V2.9996 on a new SD Card with Stretch OS on a Pi2 with a Pi3 power supply is approaching 70:00 with out any freezing problems.

Hallo,
 
I do not know the other brands, but Victron have the BMV battery monitor, that measure the actual energy passing.
Best regards,
Herman
NS, I just had to answer you, Herman!