3.3.4. Smart BatteryProtect in a lithium system with external BMS and load disconnect output
This wiring example shows a Smart BatteryProtect wired into a lithium system that is controlled by an external BMS (
). This BMS has a load and a charge disconnect output that can be wired directly to the Smart
BatteryProtect H input of the remote terminal.
As with the previous example, it is necessary to program the SBP into Li-ion mode (see chapter
If, for example, the smallBMS triggers the pre-alarm because of an imminent low cell voltage, the load output becomes free
floating (normally high) when there is an actual low cell voltage and the SBP will disconnect the load and remains off for
30 seconds, even if it receives a restart signal (H becomes high again) within this period. After this 30 seconds, it responds
immediately to a restart signal.
If the system has been switched off due to low cell voltage, the SBP will remain off for 30 seconds, even if it
receives a restart signal within this period (which is most likely the case if no other loads are connected to the
battery). After 3 attempts, the SBP will remain off until the battery voltage has risen above 13V (or 26V for a
24V system) for at least 30 seconds (which is an indication that the battery is being recharged).
SBP-65
DC loads
Smart BatteryProtect uses the load disconnect of a smallBMS
Smart BatteryProtect 12/24V
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Installation and wiring examples