Generex CS141 - Page 197

Version: 2020-09-04
197
Copyright of the European Union is effective (Copyright EU) (c) 2019 GENEREX Systems GmbH, Hamburg, Germany, All rights reserved
TEL +49(40)22692910 - EMAIL generex@generex.de - WEB www.generex.de (This and all other product datasheets are available for download.)
BACS LOG files
The BACS log files provide extensive information about your batteries managed by BACS:
- temperature values
- Charge / discharge cycles
- Internal resistance of the batteries
- Current fluctuations
- Operating time
- etc
These log files allow deep battery analyzes for both, the current system states and for any single battery state within a battery string.
In addition, these valuable data can be used to track the battery life cycle since installation and even make reliable predictions about
impending failures - important information for planning of maintenance intervals.
The BACS web manager has 30 MB of exclusively reserved memory in order to reliably save all BACS log data.
Rotating memory management provides maximizing available log files
With rotating storage management, the data is initially stored continuously up to the maximum usable storage size.
If the maximum available storage space is reached, the oldest entry is deleted in order to obtain the necessary space for the new data.
By doing so, the BACS WEBMANAGER grants a continuous data history.
Size of the time window before the oldest log files will be erased
You can actually only estimate an average time window, because the amount of data is shaped not only by the number of modules, but
also by the type of use in combination with unforeseeable incidents.
As an example:
- One single BACS module …
generates about 700 bytes in one day in normal operation without battery discharge cycles. If your system consists of only 1
module, the memory would need more than 29,000 days before the first day will be deleted to save the latest data.:
The local saved battery data log would show about 80 years - this is nearly an average human lifetime.
- A standard UPS system with 40 batteries...
will generate with 40 * 700 bytes about 28000 bytes per day in normal operation. The BACS web manager could therefore
hold and provide over 1000 days. You can assume that the 2 - 2 1/2 years are available
The crux of the standard application, however, can be found within the definition and the details of a memory calculation. In case of a
discharge cycle, the data logging frequency increases in order to ensure traceability and analysis of the discharge:
Due to the increased measuring frequency during the discharge cycle, each BACS module generates approx. 9300 bytes. When we
assume a special and very theoretical discharge scenario (normally the batteries are depleted long before), the BACS web manager
could record the discharge for a standard UPS with 40-60 batteries in this scenario up to 17-18 hours continuously.
Note:
What is such a „theoretical discharge scenario“?
Usually, a power failure itself cannot be planned, but the batteries can be found at a foreseeable site when this happens. As
soon as the EDP has been shut down, the UPS can also be switched off. How long the UPS will grant emergency power
depends on the capacity of the UPS as well as the number of devices that must be feed with emergency power.
However, there is also the possibility that you have a mobile EDP system with limited main power usage that comes with the
problem a hardware shutdown is not an option (e.g. a tectonic sensor grid). Minor power usage may lead into a very long
emergency power operating time via the UPS. In this special scenario, the battery data can provide valuable insights to
improve reliability with some limitations.
- A large UPS solution with 120 managed batteries…
When normal operation is active, the BACS WEBMANAGER would generate with 700byte * 120 units an impressive amount
of data of up to 84,000 bytes - Keep in mind that these data are not "image files", we are talking about numerical values that
are in a table and can be converted into graphic tables if necessary.
In this case, the BACS WEBMANAGER B4 can keep this immense amount of battery data for up to 238 days before the
oldest files have to be overwritten.
The data will be available for about 7-9 months.
During a discharge, the measuring frequency is increased as described above. In a very large battery system with up to 120
batteries, a BACS web manager can still hold records of the discharging process between 8-12 hours, the amount of collected
data is difficult to imagine.