what voltage is a forklift battery
If you want to know the voltage range of lithium batteries, you must first distinguish the difference between the voltage of lithium battery cells and the voltage of lithium battery packs, and also understand the types of lithium batteries, because the voltage ranges of different lithium batteries are also different. , and then understand the difference between the nominal voltage, the full voltage and the discharge termination voltage, so as to better understand the problem of how much the lithium battery voltage range is.
Lithium battery
- Understand the voltage range of lithium batteries from the perspective of lithium batteries
Lithium battery cells are mainly divided into two categories: lithium iron phosphate battery cells and polymer lithium battery cells. Their cell voltages are different due to the different characteristics of the chemical raw materials they are manufactured. The specific conditions are as follows:
(1) The full voltage of polymer lithium batteries is 4.2V, 4.35V, 4.4V, and even 4.45V. Generally speaking, 4.35V or above belong to high-voltage batteries, with relatively high energy density and production technical requirements. It is relatively high, and the price is relatively high. The discharge termination voltage (the voltage at which discharge is stopped) depends on the manufacturer’s regulations, which is generally higher than 3.2V. Now the market is basically full voltage 4.2V, nominal voltage 3.7V, termination voltage is 3.2V, the technical threshold is relatively low, the application popularity is relatively high, especially the 3C electronic products on the market now, The basic 4.2V lithium battery is used.
(2) The voltage range of lithium iron phosphate battery is 2.0 to 3.65V
The full voltage of the lithium iron phosphate battery cell is 3.65V, and the discharge termination voltage is 2.0V. Generally, the battery manufacturer in order to protect the service life of the cell, the termination voltage will be higher than 2.0V. Due to the characteristics of the battery chemical materials, the energy density of iron-lithium batteries is lower than that of polymer lithium batteries, but the safety performance is higher and the price is lower. Therefore, many batteries used in new energy vehicles are iron phosphate. lithium battery.
(3) Lithium-ion cobalt oxide battery, voltage range 2.6 to 4.2V, nominal voltage 3.6V.
The full charge voltage of the lithium cobalt oxide battery cell is 4.2V, the final discharge voltage is 2.6V, and the nominal voltage is 3.6V.
(4) The voltage range of NiMH NiCd battery is 1.0 to 1.4V, and the nominal voltage is 1.2V.
Here we need to make a brief introduction to the nominal voltage. The nominal voltage can be simply understood as the average discharge voltage, but for batteries, it is generally the average discharge platform.
- What is the voltage range of lithium batteries from the battery pack
In fact, when we buy batteries, we often see batteries with higher voltage than 4.2V, such as 6V, 12V, 24V, etc., and in many cases, the voltage of lithium batteries we use is more than ten volts. , what’s going on here?
In fact, no matter how many volts the battery voltage is on the market, as long as it is 6V or above, it is achieved by connecting lithium cells in series. For example, let’s take a 24V voltage 20000mAh capacity lithium battery for a brief introduction. If the battery cell it uses is a polymer lithium battery with a nominal 3.7V and a full voltage of 4.2V, and the capacity of a single cell is 5000mAh, how many cells does it need to achieve through series and parallel? 24 divided by 3.7 equals 6.5, then it takes 7 cells in series to reach the required voltage, and then four groups of the same series cells are combined in parallel to achieve a capacity of 20000mAh, then a total of 7 times 4 equals 28 cell.
So what is the voltage range of the lithium battery combined in this way?
You might think:
The full voltage is: 4.2V×7=29.4V
The nominal voltage is: 3.7V×7=25.9V
The termination voltage is: 3.2V×7=22.4V
So is the voltage range of this lithium battery 22.4V ~ 29.4V? In fact, this is only a theoretical value, because the battery pack generally has a battery protection board. Generally speaking, after the cells are formed into a battery, the termination voltage of the cells will be slightly higher, and the full voltage will be slightly lower. In this case, the lithium The voltage range of the battery will be smaller than the theoretical value of 22.4V ~ 29.4V. It may be 23V ~ 28V, but the manufacturer will limit the battery pack to the safe use voltage range when the lithium battery protection board is matched and designed. The specific amount will vary depending on the level of manufacturing technology of the battery manufacturer.