LIT is a battery settings mode. When switching to LIT, the S parameters should be the same as the previous default settings.
When battery voltage falls below 10V the battery BMS disconnects the battery discharge. As soon as there is PV voltage the battery BMS connects the charge and discharge. We recommend the customer set the LOAD Output turnoff at 11V so tha load disconnects before the battery BMS disconnects the discharge.
We recommend that you just leave the parameters set to AGM Lead Acid. This is how the Lithium battery BMS is designed. The AGM Lead Acid settings in the charge controller are compatible with the battery BMS.
You won’t see voltage spikes when connected to the battery (BMS), even if the battery BMS disconnects the discharge. No firmware updates are available or needed to switch from AGM lead acid to lithium.