Electric forklifts can be used for a long time
Look at the use case, look at work environment, look at worker's labor attitude, average about a year and a half.
You're talking about working hours, which is no problem for eight hours If the working hours are long, you may need two sets of battery rotation
Focus on your usage, if always load operation combined with often do not maintain, life will be shorter, if often maintenance and operating life by the use of forklift truck in strict accordance with the requirements of a bit, is usually one to two years