Using a 12V Battery in Series with a 12V Inverter

Can you connect a 12V inverter to just one of two 12V batteries in series to get a 24V battery bank? While it may seem tempting for short-term use, this approach is not recommended and can lead to battery damage. Let's explore the reasons why.

Efficacy and Risks

For very short-term use, it is possible to connect a 12V inverter to just one of the batteries in a series configuration. However, this method is not recommended for any significant duration. The main issue lies in the unbalancing of the battery stack.

When you disconnect a load from just one battery, you create an imbalance within the battery bank. This imbalance can lead to several problems during the charging cycle:

One of the batteries may become overcharged. Outgassing and deterioration can occur.

Detailed Explanation

Let's break down the problem in more detail. Batteries in a series configuration provide a higher voltage, in this case, 24V when two 12V batteries are connected in series. When you connect a 12V inverter to just one of these batteries, you are essentially removing charge from that particular battery while the other battery remains connected to the system.

During the charging cycle, one battery will become fully charged before the other. If the charging system continues to charge both batteries, the laggard battery will not catch up, leading to one battery being overcharged. Overcharging can cause several issues:

Outgassing: When a battery is overcharged, it produces gas (hydrogen and oxygen), which can be explosive. This can lead to a hazardous situation. Deterioration: Overcharging can significantly shorten the lifespan of the battery. The electrolyte, plates, and other internal components can deteriorate rapidly, reducing the overall performance and longevity of the battery.

Compensating for Small Loads

For small loads, you might be able to compensate using a battery balancer. A battery balancer can help to manage the charge distribution equally between the batteries, preventing overcharging of one battery. However, even with a balancer, an inverter is still not ideal as a small load. Inverters typically draw a significant amount of current, which can still cause an imbalance.

One common solution is to use a dedicated 24V inverter. This ensures that the load is distributed equally between the two batteries and helps to maintain a balanced charge cycle, reducing the risk of damage and prolonging the life of your batteries.

Conclusion

In summary, while you can temporarily connect a 12V inverter to just one of the batteries in a 24V series configuration, it is strongly recommended to invest in a 24V inverter for long-term use. This will ensure that both batteries are used equally, preventing overcharging and prolonging the life of your battery bank. Always prioritize the longevity and safety of your electrical systems.