AGM technology (absorbed glass mat) batteries are different. They're more expensive than wet cell batteries, but they're also less likely to fail under pressure or if you don't follow proper maintenance procedures. They also hold their charge longer than wet cell batteries do—about twice as long! This means that if you hook up your RV to a solar panel at night, there will be enough power for when you wake up in the morning without having to worry about running out of juice by midday.