Some cruisers invest in the latest electronics, engine, sails, and communications equipment but when it comes time to invest in new batteries, sometimes choose the now 100-year-old technology of lead-acid batteries or the most recent improvement to lead-acid technology (40 years old) which are AGM batteries, which have almost the same negatives as the original lead-acid battery.
Lithium batteries have only recently become available for marine use but they are quickly becoming the preferred choice for experienced cruisers and racers worldwide. You can also buy cylindrical lithium ion battery via https://nuenergystorage.com/cylindrical-li-ion-batteries/
Lithium batteries provide on average 4 times the amount of charge and discharge cycles when compared with Lead Acid /AGM batteries which greatly reduces the number of times you'll need to replace them. Lithium batteries continue to provide consistent performance and voltage throughout their lifecycle which (as mentioned previously) in the case of Lead Acid/AGM batteries diminishes substantially during their last 1/3 of life.
Because Lithium batteries can go as much as 90% discharge without any damage to the battery you can get away with much fewer amp-hours, using the example above, you may consider a 200 AH Lithium battery which would give you all your daily consumption plus more than a 30% safety net for starting functions, (can be set to shut down at 20% charge) eliminating the need for a separate starting battery. The result is a huge reduction in weight on the boat and an increase in performance.
By investing in Lithium batteries the initial cost is spread out over a much longer period. You will reduce your actual cost of ownership, increase your performance, reduce charge times by 75%, reduce engine/generator wear and tear, save on fuel costs with less weight and charge times, reduce noise, reduce maintenance, and reduce replacement costs and hassles.