[mpg_numbers_guy]

A smart charger is definitely required for charging, for that very reason.

Lithium batteries can use coulomb meters to measure SOC more accurately (Lithium Insights use a more sophisticated device called OBDIIC&C). If you keep the SOC between 20% and 90% you should be fine and extend the life of the battery verses discharging/charging them to 0% and 100%.

SOC is fairly easy to measure on lithium batteries with a coulomb meter, versus lead acid where the voltage varies under load. Other lithium chemistries are much more sensitive to things like temperature and charge/discharge rates.