3.6 Volt Lithium Battery vs. 3.7 Volt Lithium Battery: Differences and Applications
The main difference between 3.7 Volt lithium batteries and 3.6 Volt lithium batteries lies in their nominal voltage and battery capacity. The output voltage of a 3.7V battery is 0.1V higher than that of a 3.6 Volt battery. In practical use, as long as the appearance and wiring positions of these two batteries are the same, they are use interchangeably, especially in devices that allow voltage fluctuations.
Differences between 3.7 Volt and 3.6 Volt lithium batteries
The only difference is in the rated voltage parameters; there is no other distinction. According to strict standards, the rated voltage of 3.6V and the rated working voltage of 3.7V differ due to varying standards in the electronics industry. Sometimes, it refers to the maximum working voltage of a single cell, and sometimes, it refers to the minimum working voltage of a single cell.
The minimum working voltage of a lithium battery is about 3.2V, and the maximum is about 4.5V, so there is no practical functional difference between the working voltage parameters of 3.6V and 3.7V! The main difference between a 3.6 Volt battery and a 3.7V lithium battery lies in their nominal voltage and capacity.
Nominal Voltage: The nominal voltage of a 3.6V battery is 3.6V, while that of a 3.7V lithium battery is 3.7V. This difference is mainly due to advancements in battery technology. Early lithium-nickel-cobalt-manganese (NCM) batteries had a nominal voltage of only 3.6V due to technological processes. However, with continuous improvements in battery formulas and structural refinements, the nominal voltage has reached 3.7V.
Capacity: The capacities of these two types of batteries can range from several hundred to several thousand milliamp-hours, depending on the battery’s design and application needs. For example, a 3.6 Volt battery can have a nominal capacity of up to 2200mAh, while the 3.7V lithium battery can include specifications such as 1800mAh, 2200mAh, and 2600mAh. It’s important to note that 4400mAh and 6600mAh capacities are actually the result of combining multiple cells.
Applications
These two types of batteries are widely use in various instruments, testing devices, medical instruments, POS machines, laptops, and other products. They are widely adopt for their high energy density and long cycle life.
Series Use
Both the 3.6V and 3.7V versions of the 18650 lithium battery can use in series to provide a higher voltage output. This is because the voltages of the two batteries are very close, so they are safely use in series. However, to ensure the safe use of the batteries, it is recommended to ensure that the voltage and capacity of the batteries in the series are similar to avoid the risk of over-discharge or overcharging.
Why do lithium batteries have 3.2V, 3.6V, and 3.7V?
The reason is that batteries with different voltages have different characteristics.
Both 3.6V and 3.7V are polymer lithium batteries. The upper limit for polymer lithium batteries is 4.2V, and the lower limit is 2.6V, with the standard usually being 3.7V. The 3.2V battery is a lithium iron phosphate (LiFePO4) battery that can provide high-capacity discharge. This type of battery, commonly use in electric vehicles, has a long lifespan and is lightweight.
Lithium batteries can broadly divide into two categories: lithium metal batteries and lithium-ion batteries.
Lithium-ion batteries do not contain metallic lithium and are rechargeable. Lithium batteries were first use in pacemakers. Their very low self-discharge rate and stable discharge voltage allow pacemakers implanted in the human body to operate for a long time without needing to be recharged.
Lithium batteries generally have a nominal voltage above 3.0V, making them more suitable for integrated circuit power supplies.
Manganese dioxide batteries are widely use in calculators, digital cameras, and watches. To develop batteries with superior performance, researchers have studied various materials, resulting in unprecedented products.
Additional Knowledge
What is the difference between a 3.8V lithium battery and a 3.7V lithium battery?
The main difference: 3.8V can charged a bit more fully.
Most batteries are 3.7V lithium batteries, and during discharge, the voltage will drop, usually from 4.2V down to around 3.0V, so the voltage marked on the battery is not a stable output voltage.
The standard voltage for lithium batteries is about 7.4V, so there’s not much difference between 3.7V and 3.8V, except that the 3.8V battery may charge slightly more fully.
When charging lithium batteries, a voltage upper limit must be set to balance battery lifespan, capacity, and safety. The ideal charging voltage upper limit is 4.2V. The discharge voltage lower limit should also be set. When the cell voltage drops below 2.4V, some materials may begin to degrade.
Since the battery will self-discharge over time, the voltage will drop. Therefore, it’s best not to discharge below 2.4V. Discharging from 3.0V to 2.4V only releases about 3% of the battery’s capacity.
Thus, 3.0V is an ideal cutoff voltage for discharging. In addition to voltage limits, current limits are also necessary. If the current is too high, lithium ions may not enter the storage grids in time and will accumulate on the surface of the materials.
In conclusion, while there is a nominal voltage difference between 3.6V and 3.7V lithium batteries, they can use interchangeably in many applications, especially in cases where voltage fluctuations are allowed. Additionally, with advancements in technology, 3.7V lithium batteries are gradually becoming the mainstream choice due to their higher energy density and superior performance.