A lead-acid battery has a 3 stage charging profile, while a lithium battery has only one. The voltage also differs between the two. That's why you need a charge controller that can be manually programmed or changed to a lithium setting. If you want to know which setting to use, read my article about a LiFePO4. A lead-acid battery is more forgiving for temperatures. If you plan on using lithium in a place where it can freeze, you better use a battery with a. If your lead acid battery was charging directly from your car's alternator, you need to make some changes. Lithium batteries have a low internal resistance. It will demand as much. If you have lead-acid batteries, you can easily monitor the capacity of your battery by using a voltage meter. The voltage curve of a lithium battery. Lithium batteries can deliver high amounts of current if it's shorted. This will result in a current ten or more times the battery's capacity. For a 100Ah.