series and parallel connection
Contents in this article

Battery series and parallel connection

Define parallel connection and series connection

Battery series and parallel connection are done to increase total voltage and increasing Ah capacity. Series connections are done to increase total voltage. Parallel connections are made to increase total Ah of battery bank.

Battery series and parallel connection where it is used:

Initial Charging of Batteries:

Series connection of 18-20 batteries of same type/size are normally carried out in factories to initial charge batteries. When more batteries like 54 /108 batteries are to be charged simultaneously, 18 batteries are connected in series in one string. 3/6 such parallel strings will be able to connect all 108 numbers of 12V batteries

Battery series vs parallel

In a series connection, the current flowing through a single string will be the same for all 18 batteries.
When 4 such lines are connected in parallel, the current is divided between all the 3 lines. The current will be equal in all strings when the internal resistance of all four are the same. Otherwise, the current will be distributed non-uniformly. Eg 23 %. 27 %, 26% and 24 % in place of the 25% required. The charging time of all 4 lines will be different.

Difference between series and parallel connection of batteries

Battery series connection
When the batteries are connected in series as in railway undercarriages, or telephone exchanges, it is essential that the cells are matched for Voltage, Ah, capacity and electrical resistance. These batteries are generally discharged partially or completely. During discharge POLARITY. Reverse charging is totally unacceptable since the expander gets oxidized and the negative plate loses capacity. Therefore it is essential that we should match both flooded and VRLA cells in deep discharge applications., the weaker cells get fully discharged first. On further discharge, these weaker cells undergo reverse charge. (What is commonly called CELL REVERSE).

Advantages and disadvantages of series and parallel connection

Connecting batteries together, either two or more, whether in series or parallel, or series-parallel, we can increase the voltage, or capacity or even both. This allows for higher voltage applications or higher power requiring applications.

Battery Series and parallel connections in Lead-Acid battery (LAB) and Lithium-ion batteries, (LIB)
Ah capacity of single cells of lithium batteries is low, of the order of 3000 milliamps – 4000 milliamps (3-4 Ah). This requires a very large number of matched cells.
In practice, the cells are connected in series and parallel into a PACK which now becomes the unit module for making battery banks. These undergo matching. In Electric vehicles, such PACKS are the building blocks to make high voltage, higher Ah capacity batteries. A sophisticated Battery monitoring system becomes inevitable & essential for the proper functioning of lithium-ion batteries. This invariably increases the cost of the lithium-ion battery system.

In the case lead-acid batteries, cells can even have Ah capacity of 1500 Ah, 500 times higher compared to the lithium-ion battery cell. Therefore the manufacture of Li-ion batteries calls for a very high degree of control on processing parameters while manufacturing compared to lead-acid batteries.
In any case, it is necessary to measure the cell voltages and internal resistance of individual cells. Matching of cells is an essential step carried out by manufacturers.

When battery series and parallel connection are required, an equalization of current in all strings is obtained by using the circuit given in the diagram below. The interconnection or cross-connection helps in equalizing the current in all 4 strings.

Batteries-connected-in-Series-and-Parallel.jpg
Double voltage, Double capacity (Ah) 12v 20Ah
battery series and parallel connection
Series Parallel connection for battery charging

Care must be taken to ensure while connecting batteries in series, that each battery must have the same voltage and ampere hour rating. Otherwise you will damage the batteries.

 

Please share if you liked this article!

Did you like this article? Any errors? Can you help us improve this article & add some points we missed?

Please email us at webmaster @ microtexindia. com

Please enable JavaScript in your browser to complete this form.
On Key

Hand picked articles for you!

AGM Battery

AGM Battery

What does AGM Battery mean? What does AGM Battery stand for? Let us first know what does the acronym, AGM, stand for. AGM Battery full

Electrochemistry Microtex

Electrochemistry

Electrochemistry Definition Electrochemical power sources or batteries are studied under the inter-disciplinary subject of Electrochemistry dealing with the reactions occurring at the interface of electronic

Battery Recycling

Battery Recycling

Above photo credit: EPRIJournal Lead acid Battery Recycling A Paradigm for battery recycling in a circular economy Battery recycling, particularly lead acid batteries is a

EFB Battery

Guide to EFB Battery

What is an EFB Battery? EFB Battery meaning In an effort to reduce the CO2 emissions of vehicles which have an internal combustion engine (ICE),

Join our Newsletter!

Join our mailing list of 13,988 amazing people
who are in the loop of our latest updates on battery technology

Please enable JavaScript in your browser to complete this form.

Read our Privacy Policy here – We promise we won’t share your email with anyone & we won’t spam you. You can unsubscribe anytime.

Want to become a channel partner?

Leave your details & our Manjunath will get back to you

Want to become a channel partner?

Leave your details & our Manjunath will get back to you

Do you want a quick quotation for your battery?

Please share your email or mobile to reach you.

We promise to give you the price in a few minutes

(during IST working hours).

You can also speak with our VP of Sales, Balraj on +919902030022