The first step in upgrading a 12-volt lead acid battery to lithium is to choose the cell chemistry and configuration. This is a necessary step because regardless of the chemistry you use, lithium-ion batteries have a voltage that is much lower than 12. This makes it so you will have to put some amount of them in series to achieve 12 volts.
To successfully replace lead acid batteries with lithium, there are three main steps to follow. First, select the right lithium battery for your specific application. Next, upgrade the charging components to accommodate the lithium battery. Finally, ensure proper safety measures are in place for a secure and reliable battery system.
Lead acid batteries require a simple constant voltage charge to the battery while lithium ion chargers use 2 phases; constant current and then constant voltage. Unlike lead acid batteries, Lithium-ion batteries have an extremely small capacity loss when sitting unused.
Discharge Characteristics: Lithium-ion batteries can be discharged deeper than lead acid batteries without damage. This means you can utilize more of the battery’s capacity, but it’s crucial to avoid discharging below the recommended levels to maintain battery health.
Lithium batteries are a lot more power dense than lead acid or AGM batteries, so this means that a replacement lithium-ion battery of the same capacity will be much smaller than a lead acid battery. So, buying or building a lithium-ion battery for a lead acid scooter is a relatively straightforward affair.
Due to their many advantages across a wide range of applications, it's becoming more and more common to replace lead acid/AGM batteries with lithium. If you are upgrading a home battery bank to lithium and you already have a modern charge controller, the process could be as simple as installing the new batteries and flipping a switch.