If your forklift battery stops working, your business productivity will take a hit. Industrial batteries are designed for durability, but a number of factors can shorten their service life. If you take these steps to maintain your forklift battery, you can help it last as long as possible. 1. Don't over or undercharge the battery. A forklift battery should only be charged when it falls below a 30 percent charge, or as close to a 20% charge as possible.