I've been amusing myself by doubling up the size of my home off-grid solar panel/battery/inverter setup, including making up a LiFePo4 battery from separate cells and BMS, and as a result I have two 12V 100Ah gel batteries that I no longer have a use for. They are deep cycle, and the maximum charging current is 20amps, so they would make good wind/solar charged house batteries but are not suitable for alternator charging, engine starting or windlass power.  The terminals are M8 bolts.They would need to be collected, as each weighs just over 30kg. A donation to charity would be appreciated.