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 heating element inside. The ideal temperature for a lithium battery is room. 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 current from the alternator as it can handle,. 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. 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 is very flat compared to lead acid. Therefore it's unreliable to read your.
