Accumulator Li-Ion 20V, 2Ah, WAINER C2

Practical Guide to Understanding Tool Accumulators

Voltage and How to Check it

• The voltage of a battery indicates the voltage supplied and is easily checked with a multimeter. For example, a battery that says 10.8V or 12V means the same thing: the nominal voltage is 10.8V and the maximum fully charged voltage is 12V .
• Other examples include:
• 14.4V / 16.8V : Nominal voltage of 14.4V , reaching 16.8V fully charged.
• 18V / 20V / 21V : Nominal voltage of 18V , with a maximum of 21V .
• 36V / 40V / 42V : Nominal voltage of 36V , reaching 42V when fully charged.

Its Capacity and Importance

• The capacity of a battery, measured in Ah (ampere-hours), indicates how much energy it can provide in a certain time interval. It is more difficult to measure directly and can be estimated by checking the specifications of the cells inside the battery.
• An indication of capacity can be given by the weight of the battery, as higher capacity batteries have more cells or better performing cells.

Types of Cells and Their Capacities

• Tool batteries mainly use two types of cells: 18650 and 21700 .
• 18650 cells :
• Capacity: 1.3Ah to 3.5Ah
• Dimensions: 18 x 65 mm
• Weight: 40-50g , depending on capacity (higher capacity cells tend to be heavier).
• Cells 21700 :
• Capacity: 3Ah to 5Ah
• Dimensions: 21 x 70 mm
• Weight: 66-78g , depending on capacity ( 5Ah cells are heavier).

How Tension Forms

• The voltage of a battery is obtained by connecting the 3.7V cells in series:
• 3 cells for 10.8V / 12V .
• 4 cells for 14.4V / 16.8V .
• 5 cells for 18V / 20V / 21V .
• 10 cells for 36V / 40V / 42V .
• In these configurations, the capacity remains the same as the capacity of a single cell. For example, if we use 3Ah cells, the assembly will have a total capacity of 3Ah .

Increasing Capacity by Connecting in Parallel

• To increase capacity, cells can be linked in parallel, which means adding more rows of cells:
• 2 or 3 rows of cells in parallel to double or triple the total capacity.
• Thus, cells with lower capacities can be used to achieve the desired voltage and increase the capacity.

Identification and Warnings

• To identify the actual battery capacity, open the case and check the cell type. Each cell is marked with the type (for example, 18650 or 21700 ) and its capacity, which can vary from 1.3Ah to 5Ah .
• Beware of prices that are too low, which may indicate the use of lower-quality or lower-performing cells.

In conclusion

• The voltage is checked with a multimeter to ensure compatibility with the tool.
• Capacity is estimated by checking internal cells and battery weight.
• Choose batteries with quality cells to achieve optimal performance and durability in use.

Thus, we can conclude the following:

• Accumulator with 5 cells in a row :
• Minimum capacity : 1.3Ah (affordable)
• Maximum capacity : 5Ah (customized prices)
• Maximum voltage : 21V (with 5 cells in series)

• Accumulator with 10 cells :
• Cell configuration : Can be configured in 2 main ways:
• 5S2P (5 cells in series and 2 rows in parallel) :
• Voltage : 21V (nominal)
• Minimum capacity : 2.6Ah (if each cell has 1.3Ah)
• Maximum capacity : 10Ah (if each cell has 5Ah)
• 10S1P (10 cells in series) :
• Voltage : 42V (also marketed as 40V)
• Capacity : 1.3Ah to 5Ah

• Accumulator with 15 cells :
• Cell configuration :
• 5S3P (5 cells in series and 3 rows in parallel) :
• Voltage : 21V (nominal)
• Minimum capacity : 3.9Ah (if each cell has 1.3Ah)
• Maximum capacity : 15Ah (if each cell has 5Ah)

Remarks:

• The price of a battery increases with the capacity and complexity of the cell configuration.

• A 10 or 15 cell battery can be configured to provide both higher voltages (42V) and higher capacities (by parallel connection).

• The choice between voltage and capacitance depends on the specific application and the needs of the tool you are using.