The battery life of new energy forklifts is affected by multiple factors. 

Firstly, regarding the charging environment, the battery should be charged within a temperature range of 5 to 35 degrees Celsius. Although theoretically, higher temperatures can increase the battery capacity, in practice, it will actually reduce the capacity. Moreover, the quality of the battery has a significant impact on the lifespan of the forklift. 

The next factor is the depth of discharge. Excessive deep discharge causes the active substances in the part of the plate close to the "electrode core" to participate in the reaction, resulting in corrosion of the "electrode core" and an acceleration of the detachment of active substances. 

Furthermore, charging and maintenance are crucial. Following the prescribed procedures can minimize the damage to the battery and extend the service life of the forklift. 

Also, if there are any issues with the quality of the battery itself, such as a reduction in the amount of lead used which leads to poor performance of the individual cells in the battery pack, it will cause the lifespan of the entire battery pack to decline rapidly. 

Furthermore, if the charger is not compatible with the forklift, it can cause the battery to discharge and charge excessively, resulting in the deterioration of the electrode plates. 

In terms of battery maintenance, issues such as insufficient charging during the first use, not fully charging before long-term use, not charging in time after discharging, long-term deep discharge with low current or excessive charging, excessive specific gravity of the electrolyte and high temperature, long-term non-use without regular charging, internal short circuit or leakage of water and electricity on the surface, etc., all can affect the lifespan of the battery. 

The higher the usage frequency, the harsher the usage environment (high temperature, humidity, dusty air), the poorer the battery quality, the improper maintenance (unclean battery surface, failure to check connectors, insufficient electrolyte replenishment), and the unreasonable usage (frequent charging and discharging, neglecting to maintain battery power, too low remaining power), all of these will shorten the battery lifespan. 

To extend the battery life, it is advisable to choose high-quality batteries, such as those with high capacity, high charging efficiency and a sealed structure; regularly maintain the batteries, including cleaning, checking connectors and replenishing electrolyte; pay attention to the usage environment, avoiding high temperatures, humidity and dust; use the batteries reasonably, avoiding frequent charging and discharging and excessive battery usage. 

Generally, the battery life of an electric forklift is usually between 2 and 4 years. When the battery usage exceeds 3 years, the operation time shortens, the charging time significantly increases, the appearance shows deformation or damage, and the capacity drops sharply, it is necessary to replace the battery.