I bought a ECO-worthy 50ah battery & their charger, since my MK220 charger is not for Lithium batteries. It was basically a "test run" to see if lithium was "worth it" to me. I didn't have it charged 100% when I first used it to run my Livescope & Garmin 93sv setup ... but it did run them just fine for 6hrs continuous use, then quit. I figured at full charge it should last for the 8hrs I originally planned for it to work, but I haven't used it since that first trip. Since then, however, I have purchased a NOCO Genius Pro 10x3 charger ... and can now charge my lead acid starter battery, 68ah AGM TM battery, and the lithium battery at the same time.
On a side note, about the NOCO charger : It charges my lead acid & AGM batteries just like my MinnKota charger did, BUT they seem to hold their charge for a much longer period when charged by NOCO. And, even after charging those batteries with the MK charger, & putting them on the NOCO ... they did not register as 100% charged (all green lights) like they did on the MK. Not sure if the "digital" aspect of the NOCO is the reason or not, but the MK charger is not digital & is just a straight charger ... so that may be the case.
(Just a FYI in case you have any doubts on getting a NOCO charger)