When a battery sheds, it loses active material (small microparticles of lead, which are heavy) from the battery’s positive plates, which fall into a designated space or bridge in the bottom of the battery. Active material refers to the lead paste on the plates of a lead acid battery, which is a sandy, porous material. Shedding is normal and occurs over time during charging. However, shedding can occur at a rapid rate if you use an improperly sized charger, so it’s important to ensure the charger you use is compatible with your batteries to maximize battery life.