Cellwatch Configurations
Basic Configuration
Every system must have at least one Battery Monitoring Unit, one
Control Unit and one Data Collection Module.
You can then expand that BMU and CU combination by adding up to
253 more DCMs on a single fiber optic loop, each DCM being capable
of measuring 4 cells or jars (2 volts to 12 volts nominal per cell
or jar). These cells can be organized into up to 4 strings before
you need to add any extra CUs.
Multiple DCMs
So, our larger system, now consists of one BMU, one CU and up to
254 DCMs and can monitor up to 1016 cells organized into four
separate strings of any size. These four strings can be then
organized into one, two, three or four batteries, also of any size.
The batteries can all be different sizes.
All the DCMs are connected on one simple fiber optic network
Multiple Strings and
Batteries
Then we can add more cells in more batteries/strings to create,
for example, two batteries In our two batteries:
Battery A is a single string
of say 40 jars (10 DCMs)
Battery B consists of 3
strings of 20 jars (or 5 DCMs) each. (see illustration, above)
The entire battery monitoring system now consists of 1 BMU, 1 CU,
plus 25 DCMs. In addition 4 current probes, the maximum number of
probes or CTCTs that can be supported by one CU, have been shown.
These measure current from each string or battery.
Multiple Control
Units.... BIG systems
The total number of DCMs in the above example is
relatively low at 25 compared with Cellwatch's impressive overall
capacity. Remember, Cellwatch can handle up to 254 DCMs on each CU,
that's 1016 cells per CU. Because each CU has capability for 4
Current Transducers these 1016 cells or jars can be organized into
one, two, three or four strings or batteries. Cellwatch can display
up to 250 cell depictions plus each cell's data on its computer
screen.
Furthermore, Cellwatch can manage up to 31 Control
Units on a single BMU. Start doing the math and you quickly realize
that the large system envelope is:
1 single BMU with 31 Control
Units each with 4 Current Probes and 4 Temperature Probes. This
configuration provides you with the capacity for a maximum of 124
strings, organized into 31 to 124 batteries.
Each control unit can have a maximum of 1016
measurement points. hence if 4 batteries or strings were on each
control unit, they could each have 252 cells or jars! Why 252?
Remember that you must have whole DCMs on any string. You can have
quantities not divisible by four, but you cannot share a DCM between
strings. However you can only display up to 250 cells on each
Cellwatch string panel.
Overall Cellwatch has the capacity for over 31,000
cells or jars for a single Battery Monitoring System.
What about distances?
Cellwatch uses an RS-485 serial data bus to communicate between
BMU and its Control Units. Then it uses a proprietary serial
protocol on its fiber optic network. Cellwatch has specified ranges
within industry standards that are guaranteed to operate in all
environments and conditions. These are:
