If a battery is so large that it requires 2 Lithiumate masters, their outputs can be combined.
Dedicated lines
The dedicated lines of the 2 masters may be combined as follows:
- HLIM:
- Connect the HLIM outputs of the two masters directly in parallel ("wired OR")
- Configure the masters so that the HLIM is open if charging is OK, grounded if not OK
- The combined line will be grounded if charging is disabled by either master (or both), and open if charging is allowed by both masters
- LLIM and FLT: same as HLIM
- SOC:
- Connect the SOC outputs of the two masters in parallel through 1 kΩ resistors
- The voltage at the junction of the two resistors will be the average SOC of the two masters
- DCL
- Connect the DCL outputs of the two masters in parallel through diodes (cathode to the master)
- Connect a 1 kΩ pull-up resistor between the junction of the two anodes, and to the 5 V supply
- The voltage at the junction of the two diodes will be the DCL of the master that has more limiting
- CCL: same as DCL
CAN
- Set the starting ID for standard messages of one master to a different ID, so that the two masters can talk on the same CAN bus
- Add a CAN gateway to the system
- Program the gateway to read the standard messages from each master and combine them
- Program the gateway to output messages with the combined data
