This is one of the scenarios that wont work. Full 8S LFP is 3.3 to 3.2 volts per cell --> 26.4v for full 8S LFP under discharge.The stationary battery is a 8s LFP 20-28.8V 20Ah.
The battery that will be connected and disconnected, frequently a 12s 21-28.8V 280Ah lead acid battery in a electric forklift.
12S Lead-acid needs 26.4v charge voltage straight away when empty. You might get the lead acid from 0% to 5% charge but thats pretty much it.