I work for a Battery Distributor. The GEM cars are not common around here but the original batteries seem to last a long time. It is expensive to replace the batteries in them but we sell a few sets a year, some people downgrade to a standard wet battery due to cost and some people pony up the money to keep an AGM battery in them. We don't see much trouble from them either way, which speaks for the owner using them properly and/or a good charging system.

People with electric golf carts always blame problems on the batteries but it is usually lack of use and/or improper care.