Can multiple batteries be connected in parallel to increase the capacity of the inverter?

It is a common practice to parallel multiple batteries to increase the capacity of the inverter, but it does not directly increase the capacity of the inverter, but increases the overall energy storage capacity of the system. A few concepts need to be clarified here:

What is the capacity of the inverter?

The capacity of the inverter usually refers to the maximum output power it can provide, that is, how much direct current the inverter can convert into alternating current. The capacity of the inverter is determined by the design of its internal electronic components (such as semiconductor switches, inductors, etc.), independent of the number of batteries.

How to increase the capacity of the inverter?

If you want to increase the output power of the inverter, then you usually need to replace a more powerful inverter, rather than by increasing the number of batteries to achieve this. Increasing the number of batteries can increase the energy storage capacity of the system, but it does not directly increase the output power of the inverter.

The function of parallel batteries

Connecting multiple batteries in parallel increases the system's energy storage capacity, which means:

Increase storage time

Connecting multiple batteries in parallel can increase the total power of the system, so that the system can support longer power supply under the same load.

Increase peak power output

In some cases, a parallel battery can briefly provide a larger peak current output, but only if the inverter itself can withstand this additional current.

Precautions for parallel batteries

Battery matching

When connecting batteries in parallel, ensure that all batteries have the same voltage and capacity, otherwise it may cause current imbalance and even damage the battery pack.

Battery status consistency

All batteries should be in a similar charging state, otherwise there may be an imbalance when charging or discharging, causing some batteries to overcharge or overdischarge.

Battery protection circuit

In the parallel battery pack, there should be appropriate protection circuits to prevent overcharge, overdischarge, and other abnormal conditions.

Battery Management System (BMS) 

The Battery Management System (BMS) is used to monitor and balance the status of the battery pack to ensure safe operation.

Practical application case

In practical applications, such as solar power systems or uninterruptible power supply (UPS) systems, multiple batteries are often connected in parallel to increase energy storage capacity. The goal is to ensure that the system still has enough power to support the load in the event of insufficient solar power or a power outage from the grid.

Sum up

Paralleling multiple batteries can increase the energy storage capacity of the system, but it does not directly increase the output power of the inverter. If your goal is to increase the output power of the inverter, then you need to consider replacing a more powerful inverter. If your goal is to increase the storage time or peak power output capacity of your system, then paralleling multiple batteries is an effective solution. However, it should be noted that the matching of all batteries must be ensured when the battery is connected in parallel, and necessary protective measures must be taken.