Lead Acid vs. Lithium: Voltage Sag
You may be familiar with the voltage of your boat or RV`s battery bank sagging, or dropping to 11V or lower when trying to run a high-power load such as your winch, windlass, or air conditioner. When running a heavy AC load off the inverter, the voltage could drop below the low voltage cutoff, causing the inverter to turn off when you need it most. Likewise, if you are running a DC load like your bow thruster directly off the battery bank, you need it to maintain a high enough voltage for it to work when you really need it to work. Due to lithium batteries` voltage curve and ability to handle high current, loads like these will not cause the voltage to drop dramatically, eliminating the problem of voltage sag.
Lead Acid vs. Lithium: Size and Weight
With a higher DoD, higher cycle count, and higher charge/discharge rate, it`s easy to see how using lithium batteries in your RV or boat saves space by requiring a physically smaller battery bank-and I don`t need to explain the advantages of saving space in an already tight spot. But there`s yet another physical benefit of replacing lead acid batteries with lithium for RV and marine applications: Lithium batteries also don`t have the crazy weight from being made with lead! Lighter weight means higher fuel efficiency, saving you additional money in gas or diesel costs.