All batteries, regardless of their chemistry, self-discharge. The rate of self-discharge depends on the type of battery, the age of the battery, and the storage temperature the batteries are exposed to.
How long will golf cart batteries last when not in use?
They may last anywhere from months, up to 5-7 years under the right circumstances. But when left idly in high temperatures for long periods of time (such as in a hot garage in the summertime) or when left unused for months, it can really take a toll of the lifespan.