The CellMate-K9 is suitable for a shared wiring harness that can be used in conjunction with the WatchMon supervisor.
Cellmate-K9 is fabricated with 4 Ohm resistors to suit LiFePO4, Lithium-Ion or custom chemistry. This results in an Auto-Level (balancing) function of approximately 500mA achieving more than 6 Ah/day balancing adjustment for each cell.
The system operates in a four-cycle sequence of 5-second intervals. This allows for approximately 50% duty cycle between adjected cells in series to not impact cell voltage sensing or exceed wiring or fuse ratings.
When balancing is required, the four stages are as follows ODDS, EVENS, resting, then sensing and repeat. Ensure that the balancing wires are dedicated for this function and do not share any circuit with other devices.
If you run other devices that need their own circuit, take time to consider the power of other equipment, like supervisors which should have their own cabling.
Be careful not to have shared wiring with adjacent CellMate-K9 from higher voltage series as these will impact each other.
CellMate-K9 has been designed to allow a 60mm Fan to be mounted to enhance balancing performance if the customer desires.
*Note that fans and standoffs are not supplied when ordering.
Cable joins the CellMate-K9 to WatchMonCORE and/or CellMate-K9 to additional CellMate-K9s in a daisy chain with a terminator on the last CellMate-K9 in the daisy chain.
Note: Each cable can be 1.5m, capable of up to 20 CellMate-K9 monitoring modules for a CMU network. However, will require external 5v power beyond 6 units.
Contact us for more details if you consider this application.
Adopt twin twisted pair cable with sufficient core to ensure no voltage drop 22-26AWG tinned and multi-strand. The cell can be in series, parallel or multi-string as each cell monitoring module is fully isolated from the CMU port. Relocate the loop back to the end of the network.
Maximum length of cable to connect two or more CellMate-K9 together? We have tested to 10m total length combining all sections, beyond this is experimental and we cannot advise further.
It is OK to use the CAT5 network pair (This has 4 twisted pairs. Make sure to use multi-strand patch lead not the in-wall solid core variant.) *Shielding is generally not required.
For extra 5V power to the supervisor, with a supply above 30Vdc (i.e. 48V battery pack voltage), we highly recommend always connecting to an isolated DC-DC (ideally 24Vdc). This power can be injected into the CMU port pin for 5V and GND for the CellMate-K9, and ensure that the CMU ground pin to the supervisor is connected for the communication to work.
Consider the following booster power to run the system:
Note: Ensure fusing within 15cm of the cell terminal or closer if possible. Ensure the wiring gauge is appropriate and avoid using over-rated cables. Consider putting it into a protective cover when combining multiple cables.
We typically recommend hooking up your typical 22-26 AWG hook-up cable to an in-line 3A fuse (preferably ceramic sand-filled) to extinguish the DC arc.
Read more: Battery Cabling and Wiring Best Practices
Remember: When wiring multiple CellMate-K9s, you need to treat each as an independent pack so that both the positive and negative of each module go direct to the cells. They cannot have a shared wire from one module to the next, nor drop the negative and only run one of the two.
Each needs to match your cells as they are built for example if in groups of 8 or something else. Ideally, each should be approximately the same voltage, with roughly the same number of cells in series, and not just have the last monitor a couple of cells.