Connecting Different Batteries in Series and Parallel

Wiring two or three batteries in parallel is a technique that is improperly used to expand the intensity or amount of electrical charge, that we can obtain from an external power source, this generally comes from two batteries with identical capacity. Let’s dig into the thing about connecting different amp-hour batteries in parallel.

Connecting Different Capacity Batteries in Parallel:

This type of setup is carried out using interconnection cables that connect them through the positive terminals of both batteries. On the one hand, use another interconnection cable that connects them through the negative terminals. On the other hand, what is achieved with this is to add their currents in amperes and keep an identical voltage. Now, why is it not recommended, what are the disadvantages of carrying out this type of installation? What do we expose ourselves to when we connect two batteries in parallel? 

Can I wire two different amp-hour batteries in parallel?

Are you wondering why users shouldn't connect two different batteries in parallel? This can cause an overload of the battery closer to the current input, as well as an inadequate charge of the battery that is further away If you are connecting different batteries in parallel. The overload means that there is an increase in electric current, generally due to overheating of the same - either due to heat, as well as improper installation. The problem with doing so is that it may lead to an explosion, and bring all the negative consequences to us. Similarly, in this case of the battery is further away from the current input. And by not charging properly, it will be constantly degrading, so its service life will be shorter and we will waste money.

Another problem with putting two different batteries in parallel is that the first battery, which is closer to the current input, and it will withstand higher current and higher voltage for charging, which can lead to the risk of a short circuit or a fire.

What is going to happen in this case? By connecting different batteries in parallel, the circuit will be closed and generate an unbalance of the currents. As the capacities of these batteries are no longer identical, they will give up electrical charges between each other to equalize the voltages when they are linked together. That is to say, its operation is incorrect, which leads to premature aging of both or they will be damaged in this operation. Another of the main consequences of the installation of batteries in parallel is the interconnection cable. Besides, they suffer an alteration in their electric resistance which can cause- in parallel - to a destabilization of the whole, as well as affect the service lifespan of the batteries that are connected.

Please note, when undergoing a variation in the electric resistance that the cables support, they will overheat because of the high intensity that circulates through them, and this operation can lead to a fire in our home or place where we have connected the cables.

This is why we do not recommend it, and if used, it is best to be carried out, by experts who are very aware of the operation of electricity and who take the necessary safety measures. Thus, the installation creates the minimum problems in terms of wiring, as well as the position of the batteries and, of course, the operation of these in parallel.

Meanwhile, if this type of battery connection is carried out in parallel, we recommend that this setup is reviewed periodically to verify that there are no problems. For example, making use of ohmmeters to measure electrical resistance, as well as the voltage, electrical current, and any relevant aspect of this installation.

What will happen when connecting two batteries of different amp-hour ratings in series?

This setup will definitely work when you connect two batteries of different amp hour ratings in series, however, it will be a high chance to damage both batteries during charge and discharge cycles.

Generally, this type of connection is made in isolated solar photovoltaic installations. Many people consider that this is a great option to expand the charge of solar batteries.

What is sought with this is that the solar batteries expand the charging capacity so that, their use can be prolonged when making use of the solar energy stored through the solar panels.

This is a good idea to install solar energy batteries in series to make better use of the energy generated by photovoltaic panels, and this can help to store much more energy sources.

We do recommend using LiFePO4 batteries in series on the solar system, this can help users save much cost and be safe on using it.

What is the connection of batteries in series?

The connection of batteries in series is different from batteries in parallel, which is an installation by connecting the opposite poles of a battery with the opposite poles of another battery. That is to say, the negative charge pole of one battery is connected to the positive charge pole of another battery by using an interconnection cable, usually using a sufficiently small cable to connect both batteries. This process is repeated with the positive charging pole of the initial battery connecting to the negative charging pole of another.

In this way, the sum of the voltage or potential difference of both batteries is achieved, thereby maintaining the intensity or electrical charge. Unlike the connection of batteries in parallel, batteries in series do not pose a danger to our health and integrity since they only allow the current flow when there is consumption.

As long as they are not used, the batteries will remain idle. Of course, for the installation to be safe, and for us to obtain the required voltage, batteries connected in series must have identical capacities.

Conclusion

The terms series, parallel, and series-parallel are likely familiar to everyone who has ever used batteries, but what exactly do these terms mean? They are the act of connecting two or more batteries, but why would connect two or more batteries? By connecting two or more batteries in either series, series-parallel, or parallel, you can increase the voltage or amp-hour capacity or even both; This allows for higher voltage applications or power-hungry applications. Please note that don't connect different voltages and capacities of batteries in series, parallel, or series-parallel. That will cause damage or shorten their lifespan.