Several things are well know about Lithium batteries
Batteries that are not heated or maintained within a heated compartment are not to be charged when cold, they can be discharged aka used but not recharged
They can be charged with a lower voltage and not harmed , {they will just not reach will recharge} but this for not harm Lithium as they do not develope a damaging hardening coating like lead plates,
Over voltage is dangerous it can cause Thermal Runaway and fires,
There are some LiFePo batteries that can accept normal RV converter charge voltage and are advertise as drop in replacements, no special charger needed, Battle Born might be one of them,
The good ones, charge at one set voltage do not need special charger patterns, and do not use,/,need a float voltage, just charge at the set voltage, and leave them alone or use them, then recharge