Using charge controller to power an inverter with 2 unlike battery banks

[burgboy]

Hello Everyone. I was thinking about a setup using solar charge controllers from two separate lithium and lead banks into a single inverter.

The charge controllers have anti reversal diodes to prevent backflow. Will this system work?

Problems i see are minimum input voltages: solar for dc applications usually start at 18v. Will having the batteries power the controllers at the "solar" slot be an issue at 14-12 volts input?

Is there a better solution than using these controllers as middlemen? Another problem I forsee is the charge controllers having limited discharging current capacity.

My set up is in an rv, so Perhaps in the interest of spending the minimum on parts it would go something like this:

Alternator + generator being naturally suited for charging Pb, is hooked to them directly.

Solar panel bank 1 is hooked to Pb charge controller, then to Pb batteries. Solar panel bank 2 is hooked to Li charge controller, then to Li batteries. Li batteries are then hooked to inverter input solar charge controller. Inverter input solar charge controller is hooked to Pb batteries and inverter directly at the 'battery' slots on charge controller.

Batteries have a victron battery protect set to cut off at 11.8 volts from the inverter input solar charge controller to the inverter.

Both battery banks have 150 amp breakers from themselves to the inverter.

How would this system fare for combining two battery bank chemistries?

 

[time2roll]

Combining the batteries is a fools errand. Either have two systems or let the FLA go and a second LFP.

 

[jasonhc73]

There is never two batteries.

As soon as any battery is connected to another battery, there is only one new single battery with just one + and one -.

 

[Lywyn]

I am considering a similar project.

Could this be done using reverse-protection diodes connected to each battery bank? They would protect each bank from the voltage/amperage discontinuities between the banks.
My (very limited) understanding is that the Li batteries would take the bulk of the draw until they are close to fully discharged, then the Pb batteries would ramp up.

 

[bravo6]

I am considering a similar project.

Could this be done using reverse-protection diodes connected to each battery bank? They would protect each bank from the voltage/amperage discontinuities between the banks.
My (very limited) understanding is that the Li batteries would take the bulk of the draw until they are close to fully discharged, then the Pb batteries would ramp up.

Might work. I used to wire systems using diodes wired the other way around for split charge systems on RV and boats. Single alternator charging two batteries through diodes to allow charge voltage to both batteries but prevent discharge between the batteries. In theory it should work the other way too.