Because of the highly capacitive DC inputs/outputs of large inverters, they may present electrically as a short circuit on initial connection. To accommodate the resulting current spike during startup, there is a programmed delay to the short circuit protection on the BMS. For large inverters (>5kW), users should start multiple batteries at once, by resetting them at the same time. Follow this procedure to get up and running:

  1. With the BMS and breaker off, connect all leads as per the regular installation recommendations.
  2. Hit the RESET button on all the connected BMS units.
  3. Wait until the BMS powers on and the screen reads normally.
  4. Flip the breakers in quick succession. 
    1. You have a default Precharge time of 2 seconds to accommodate large inverter DC inputs/outputs.
  5. If the screen reads "OCP" you have triggered the overcurrent protection on the battery.

If you are still having issues, Precharge can be adjusted, if necessary, using the Rolls LFP Desktop Software. Please contact support at or submit a ticket to troubleshoot any other potential issues, and then proceed with authorization of the change in settings.