EcoTech’s firmware might default the pump to pulse mode while on battery to extend runtime. If that’s the case, there may not be a way to override it unless there’s a firmware update allowing more control.
That said, it’s still worth trying a few things just to see:
When the pump is in battery mode, check if you can adjust the backup speed settings. Right now, both are set to 25%, which might be triggering some kind of power-saving behavior.
Try manually entering battery mode and changing settings while it's running on backup - some options only become adjustable then.
If it was never calibrated in battery mode, running calibration might help.
If none of that works, you might want to reach out to EcoTech support and see if this is just how the firmware is designed to behave.