Make sure you use the correct converter/charger if you do a lithium swap.
I have been researching these batteries for awhile and still learning.
“You have to use almost all of the LiFePO4 batteries capacity before a lead acid charger will start charging again. A LiFePO4 specific charger will trigger bulk stage to start re-charging at typically 13.1-13.2V ensuring is starts charging again when it is still at high states of charge, not very low states of charge when it is going to be too late. Think about this when using solar to charge your batteries. When the sun comes up in the morning, a lead acid solar charge controller may not start charging at all regardless of the time of day if it thinks the battery is already charged based on the voltage it is reading as the re-bulk voltage hasn't been met. It will just stay in float stage. You may loose part or all of the days sunlight before getting any charge into the battery at all, leaving you with little to no charge and potentially flat batteries overnight.”