November 11, 2022
Lithium Battery Series and Parallel Definition
Due to the limited voltage and capacity of the single battery, in actual use, a series-parallel combination is required to obtain a higher voltage and capacity to meet the actual power supply requirements of the device.
- Lithium batteries are connected in series: the voltages are added, the capacity remains unchanged, and the internal resistance increases.
- Parallel connection of lithium batteries: the voltage remains unchanged, the capacity is added, the internal resistance is reduced, and the power supply time is extended.
- Lithium batteries in series and parallel: There are both parallel and series combinations in the middle of the battery pack, which increases the voltage and capacity.
- Series voltage: 3.7V single cells can be assembled into a battery pack with a voltage of 3.7*(N)V as required (N: the number of single cells)
Such as 7.4V, 12V, 24V, 36V, 48V, 60V, 72V, etc.
- Parallel capacity: 2000mAh single cell can be assembled into a battery pack with a capacity of 2*(N)Ah (N: the number of single cells) such as 4000mAh, 6000mAh, 8000mAh, 5Ah, 10Ah, 20Ah, 30Ah, 50Ah, 100Ah, etc. .
Lithium Battery Pack
It refers to the processing, assembly and packaging of lithium battery packs. The process of assembling lithium batteries into a group is called PACK, which can be a single battery or a series and parallel lithium battery pack. Lithium battery pack is usually composed of plastic shell, protective plate, battery core, output electrode, contact piece for connection, and other insulating tapes, double-sided tapes, etc.
- Lithium battery: the core part of the finished battery
- Protection board: Plays the functions of overcharge, overdischarge, overcurrent, short circuit, and NTC temperature control intelligent protection.
- Plastic shell: the supporting skeleton of the entire battery; the positioning and fixing of the protection plate; carrying and limiting all other non-shell parts.
- Terminal lead: Various terminal wire charging and discharging interfaces can be provided for various electronic products, energy storage products, and backup power supplies.
- Nickel sheet/bracket: connecting and fixing components of the cell
Lithium Battery Series and Parallel Combination
Due to safety reasons, lithium batteries must be connected to an external protection board for monitoring each battery. It is generally not recommended to use batteries in parallel. If they are connected in parallel, the consistency of battery parameters (capacity, internal resistance, etc.) must be ensured. The batteries used in series must also have the same parameters, otherwise the performance of the battery pack will be much worse than that of a single cell.
The purpose of lithium battery pairing is to ensure that the capacity, voltage, internal resistance, and effect of each battery in the battery pack are consistent. Inconsistency will lead to various parameters during the use of the lithium battery pack. The distance is farther away, resulting in voltage imbalance. After a long time, it will be overcharged, overdischarged, and the capacity will not be exerted, causing the danger of explosion and fire.