Add Lithium to Lead Acid Battery Bank

[Cuemaker]

A friend uses lead acid batteries for his solar system & wants to add lithium batteries to it.
I know it's a bad idea & I have tried to talk him out of it to no avail.
Just curious what will happen!
He has a 48v system with 3 banks of lead acid, 24 batteries total, 8 in each bank.
Going to add 48v 300ah lithium battery bank, all connected to the same buss bar.
Has anyone tried this?

 

[sunshine_eggo]

The LFP will do almost all the work. 80% of the working voltage of LFP is above the resting voltage of FLA.

The lead will be sitting there doing very little; however, due to their inefficiency in absorption, you'll need to recover about 10-15% more energy than the cap of of the FLA bank due to full charge.

 

[seneysolar]

Dont forget to disable any equalization charge feature or temp compensation that may be programmed into the CC for the lead acids. There will be very specific voltage settings for the LFP, the lead acids are just along for the ride now.