The operating voltage is obtained by connecting several cells in series;
Add each cell voltage to get the total terminal voltage.
And add total ampere hours to achieve higher capacity.
Most chemical batteries can be connected in series or parallel using the same battery type with the same voltage and capacity.
As long as you don’t mix different brands and sizes.
Cell imbalance is due to weak cells because, like the “barrel effect,” the strength of the battery is also determined by the weakest link in the chain, which is essential in tandem, where the cells of the storm are joined together to form a link (Figure 1).
Figure 1: Compare batteries and chains.
The batteries are connected in series to increase the voltage to form a chain, and the increased current load in parallel represents the double chain.
Weak batteries are depleted faster than strong ones and charged faster than strong ones.
When it discharges, the weak cells are emptied and whacked by the stronger batteries.
When used under heavy load, the battery must match multiple chains of cells.
(See: Cell mismatch, equilibrium).
Single Cell Applications
The most straightforward battery pack that does not need to be matched is a single cell structure, and the protection circuitry of a small lithium-ion battery is direct.
Phones and tablets, for example, come with 3.60V lithium-ion batteries;
The wall clock runs on a 1.5V alkaline battery;
Watch and memory backup, etc.
Most are deficient in power applications.
Battery voltages using 3.7 volts and above are lithium manganese and other lithium-based systems, which promote higher watt-hours (WH).
The argument goes that the low internal battery resistance maintains the voltage at high loads.
For manipulation purposes, these cells are 3.6 V cells.
(See confusion with voltage)
Portable devices that use batteries with two or more cells in series require higher voltages.
Figure 2 shows a battery pack consisting of four cells with 3.6 V lithium ions and can produce a rated voltage of 14.4 V.
In contrast, 12v can be generated from a single battery lead acid string with 2v/cell, while 6v can be generated from four alkaline batteries with 1.5 v/cell.
Figure 2: Four batteries in a wire can increase the voltage, but the capacity remains constant.
If you need a battery with, say, 9.50 volts, you’ll need to connect five lead-acid, eight nickel-hydrogen or nickel-cadmium, or three lithium ions in series.
You don’t need to be too precise, as long as the voltage specified by the device is lower than the terminal battery.
Most devices drive batteries that can withstand a specific voltage. For example, a 12v supply can replace a 9.50 V supply, but the battery must follow the discharge terminal voltage regulation.
The high-voltage battery in an electric vehicle divides the battery pack into modules composed of a certain number of cells.
If a battery fails, the battery must replace the affected module.
But with a new battery and a new module, there may be a slight imbalance.
(See also: How to fix a battery Pack)
Figure 3 illustrates a “cell 3” battery that produces a 2.8V operating voltage drop instead of a total 3.6V operating voltage drop and reaches its termination point earlier than a standard battery.
A “low battery” message will be sent when the device is turned off if the voltage plummets.
Figure 3: The voltage drop caused by the faulty batteries being connected in series can cause the device to be cut off in advance.
The batteries in the drone need a high-load current remote control. If one of the batteries in the series is insufficient, the voltage will drop.
Extracting the maximum current can cause a breakdown because it weakens the cell.
But this anomaly can only be identified when the battery analyzer is used to check the battery capacity or balance, not when the voltage is read after charging.
Tapping into a Series String
A common practice to obtain lower voltages is to use lead-acid arrays in series.
Heavy equipment that requires 12v power for auxiliary operation is running a 24v battery pack, and the battery can quickly obtain this voltage halfway through.
Similar to lead acid results, lithium-ion and nickel-based batteries are familiar tappings and reduced cycle life.
Newer devices use DC-DC converters when they want to use the correct voltage.
The auxiliary systems are electric and hybrid vehicles or separate low-voltage batteries.
If more current is required but not available or not designed, the battery can connect one or more batteries in parallel.
Most can configure the battery’s chemistry in parallel without severe consequences.
Figure 4 shows the cells arrayed in P4 with four parallel connections.
The illustrative components remain rated at 3.60 V but benefit from quadrupling capacity and uptime.
Figure 4: Four cells in parallel with parallel cells (4P). When the voltage remains constant, the capacity of AH and operation increases.
High resistance or open circuits in series circuits are more critical than in parallel circuits, but this is not true for a failed cell, reducing the total load capacity.
On the other hand, a short circuit can have more severe consequences because the energy of the faulty battery is absorbed from other batteries, which can easily create a fire hazard.
Most of the so-called short circuits are slight self-discharge increases, but complete short courses can occur through reverse polarization or dendrite growth.
When a failed battery shorts, fuses in a large battery pack, disconnect it from a parallel circuit.
Figure 5 illustrates an incorrectly configured parallel battery.
Figure 5: A weak unit in parallel/connected to a faulty unit will reduce running time due to reduced capacity but not affect voltage.
A short circuit in the battery can overheat and cause a fire.
On larger batteries, fuses prevent high currents by isolating the battery.
Figure 6 shows the standard cell sizes that enable flexible series/parallel configurations and achieve the required voltage and current ratings.
The sum of the voltage multiplied by the current is the total power; 12.24 watt-hour is the 3.6V (nominal) battery multiplied by 3,400 mah.
Four 18650 power cells can be connected in series and parallel, each at 3,400 mA, resulting in a total of 48.96Wh of 7.2V rated capacity.
The 97.92 WH produced is combined with eight batteries and can be carried or transported on aircraft without the limit of Class 9 hazardous materials.
(See: Airlift lithium batteries.) Flexible packaging designs can be made for ultra-thin batteries that require a protective circuit.
Figure 6: Four-cell series/parallel connection (2S2P) provides maximum design flexibility.
Aid in voltage management is due to the parallel batteries.
Lithium ions are suitable for series/parallel configurations, but the battery needs to limit the hold voltage and current.
Integrated circuits (ICS) can supervise up to 13 lithium-ion cells that are various cell combinations.
Custom circuits must be made if larger packs are needed, such as electric bike batteries, hybrid cars, and Tesla Model 85.
Terminology to describe Series and Parallel Connection
Industrial batteries require batteries to be connected in series and then in parallel.
An example is 2S2P. Lithium-ion batteries always need to make parallel cells first and then parallel cells in series.
From a voltage control point of view, complexity is reduced if multiple units are connected in parallel and then added.
Series, then parallel, to meet the chemical shuttle mechanism balance charge top, then placement may be more common in an excellent package, “2S2P”;
2p2s will be mentioned in the white paper release when parallelizing serial strings
Simple Guidelines for Using Household Primary Batteries
• Battery contacts should be kept clean.
The cell structure has eight contact points that increase resistance at each contact point.
• Do not mix batteries;
All batteries must be replaced when power is low.
The weakest link in the chain determines the battery’s overall performance.
• Observe polarity.
Instead of increasing the battery voltage, the reverse battery will decrease.
• When the device is no longer in use, remove the battery to prevent leakage and corrosion.
This is very important, especially for zinc-carbon protocells.
• battery cannot store loose batteries in metal boxes.
To prevent short circuits in the wires, separate batteries must be placed in small plastic bags.
And don’t carry loose cells around with you.
• Children must stay away from batteries.
If swallowed, the battery can cause stomach walls to decay, and the current can be a choking hazard.
If the battery ruptures, it can cause poisoning.
(See also: Battery health Issues)
• If the battery is damaged, primarily if the battery can’t recharge it, don’t recharge it.
Because it causes hydrogen to build up and then explode.
Simple Guidelines for Using Secondary Batteries
• Observe polarity when charging auxiliary batteries.
A short circuit in the circuit, resulting in a dangerous condition, can also be caused by polarity reversal.
• Remove the fully charged battery from the charger.
Users may not use the correct trickle charger, and the battery may overheat when fully charged.
• Charge at room temperature only.