How to choose electric forklift batteries?
In recent years, the development of new energy in China has been booming, and lithium batteries have rapidly improved in technology, but their prices have dropped rapidly, causing a great impact on the existing lead-acid battery market. After calculation, everyone found that the price of lithium batteries is not much different from lead-acid batteries, and they are easy to use. They can be charged at any time without damaging the battery, and their weight and volume are reduced by more than half. This has led many electric forklifts, electric transport vehicles, golf carts, etc. that used to heavily rely on lead-acid batteries to switch to using lithium batteries.
Lithium batteries have many advantages, but safety and reliability are their weaknesses. It is not easy to make good lithium batteries. As users, what we need are safe and reliable high-quality products. So how should we choose power lithium batteries such as electric forklift lithium batteries?
The first step in finding high-quality products is to understand the manufacturer's brand, scale, technical strength, and philosophy. Focusing on building a big brand, persistently producing excellent products, emphasizing reputation, having a huge scale, investing heavily in research and development, and having many years of experience in the industry are the foundations for producing excellent products. If there are any inconsistencies, the product will not be very good. We can check the establishment time, past industry experience, technical strength including patents and specialties, brand influence, scale, and whether there is a bad credit record of a company. If we understand the manufacturers one by one according to these terms, even if we purchase online, there is a great chance to buy satisfactory and good products.
Next, we will examine the two main components of lithium batteries for electric forklifts: battery cells and BMS (which can be said to be a more complex protective board). The battery cell is the main body for storing electrical energy in lithium batteries, and it is the body of the entire battery. Its quality directly affects the quality of the battery pack. The requirements for lithium batteries in electric forklifts and electric vehicles are very similar, so choosing this type of power lithium battery cell is the best choice. Thanks to the rapid development of new energy vehicles in China in recent years, the technology and safety of automotive power lithium batteries have developed rapidly, and the production has also greatly increased, providing a sufficient source of battery cells for electric forklifts. As long as the battery cells are produced by domestic first-line brand car lithium battery manufacturers, the quality is still good. If the battery cell manufacturers provide guarantees, you can use them with confidence. It should be noted that many unscrupulous businesses use batteries from unknown manufacturers, even dismantling or recycling batteries, and sell them directly to consumers without testing. This type of battery has no guarantee in terms of performance, capacity, and safety. Everyone must keep their eyes open.
BMS is a very important component besides battery cells, which includes basic protection functions and some auxiliary functions. BMS builds a safety barrier for lithium batteries through functions such as charging, discharging, and short-circuit protection. Of course, a BMS with complete functions and good quality comes at a high price. Some unscrupulous merchants, in order to save costs, even skip this, which poses a great security risk to users. Although problems may not occur immediately, they are inevitable. There is no small matter in front of safety, and this money cannot be saved. Moreover, we should try to choose well-known BMS brands with good reputation. The simple way to determine whether there is a BMS inside is to discharge and observe. If the battery is not suddenly protected at the standard discharge cut-off voltage, that is, the voltage suddenly drops to zero volts, but gradually decreases, then basically there is no BMS inside. Of course, we can also directly open the battery to check if there is a BMS inside.
The active balancing function is the second main function that BMS needs to provide.
Forklift lithium batteries are usually composed of multiple battery cells connected in series. Over time, the voltage difference between the battery cells increases due to consistency deviation and accumulated deviation, and the usable capacity rapidly decreases until it cannot be discharged. The capacity of forklift lithium batteries is generally above 150Ah, and traditional passive balancing methods have little effect. If BMS does not provide active balancing function, it may feel that the capacity of the battery pack has decreased significantly after six months or a year of use, and the decline is obvious. The cost of active balancing circuit is very high now, almost the same as the cost of other parts of BMS, so many BMS are not equipped with this function, which will affect the service life of the battery. Active balancing technology uses energy transfer to balance, which basically does not generate much heat, while passive balancing uses high voltage cells to generate heat through resistors and consume a portion of the electricity, thereby achieving voltage balance between the cells. Therefore, a clear difference between the two is whether they generate heat during operation. We can use this method to determine whether it is an active equilibrium. Another simple method of identification is to check if your battery can be charged to the maximum limit voltage every time it is charged. If not, it indicates that the battery cells are unbalanced and the BMS does not have active balancing function. This method is suitable for batteries that have been used for a period of time. If the charging limit voltage cannot be reached at the beginning of use, it indicates that there is a problem with the battery.
