Sproat Lake, Vancouver Island, BC

Do I Need A Parallel Battery Bank For Redundancy?

Do I Need A Parallel Battery Bank For Redundancy?

16-6 volt batteries in series parallel

Should I Have A Second Set Of Batteries In Parallel For Redundancy In My Off-Grid System?

  • Do I Need A Series And Parallel Battery Bank For Redundancy?
  • What are the Advantages of a second battery group?
  • What are the disadvantages of a second battery group?
  • Considerations For Your Decision
  • Conclusion
16- 6 volt batteries in series parallel
16 – 6 volt batteries in series parallel creating two separate 48 volt banks

Do I Need A Series And Parallel Battery Bank?

In the telecom world, where I used to work with extensive battery setups for backup power, redundancy was a key principle. We always had a second set of batteries as a backup, which was connected separately as both an A bank and a B bank.

Now, in the context of our off-grid solar system, should we apply a similar redundancy approach, as we did with the A and B banks in the telecom world?

Whether you should have a second battery group in your bank for redundancy depends on your specific needs and priorities. Here are some advantages and disadvantages to consider:

Telecom Battery Installation with zone 4 earthquake precaution battery stand
Telecom Back Up Battery System

Advantages of having a second battery group for redundancy:

  1. Increased Reliability: Redundancy can significantly improve the reliability of your off-grid power system. If one set of batteries fails, the second set can provide backup power, ensuring uninterrupted energy supply.
  2. Reduced Downtime: In situations where continuous power is critical, having a backup battery group can reduce downtime associated with maintenance, repairs, or battery failures.
  3. Extended Battery Life: By using both battery groups alternately, you can extend the overall life of your batteries. Batteries tend to last longer when they are cycled less frequently.
  4. Capacity: When you introduce a second set of batteries in parallel, you effectively double your storage capacity.

Disadvantages of having a second battery group for redundancy:

  1. Cost: Redundancy comes at a cost. Adding a second battery group means purchasing more batteries, which can be expensive. This cost includes not only the batteries themselves but also additional components to connect the groups.
  2. Space: Having two sets of batteries will require more physical space, which may not be feasible in some installations.
4 separate 48 volt Lithium Batteries in Parallel
4-48 volt Lithium Iron Phosphate Batteries In Parallel

Considerations for Your Decision:

  • Criticality: If your power needs are critical (e.g., for medical equipment, security systems, or remote communication), the advantages of redundancy may outweigh the disadvantages.
  • Budget: Assess your budget and whether you can justify the additional cost of a second battery group.
  • Space Availability: Ensure you have enough space to accommodate two sets of batteries and the associated equipment.
  • System Design: Consult with an expert in off-grid power systems to design a setup that meets your specific needs and incorporates redundancy effectively.


If your reliance on a consistently powered system is paramount, and any momentary power loss is simply not an option—particularly for customers with such stringent demands—then the decision to opt for redundancy becomes an evident and straightforward choice.

In summary, having a second battery group for redundancy can be valuable in situations where uninterrupted power is critical. However, it comes with added costs, complexity, and space requirements. Carefully evaluate your specific needs and budget to make an informed decision.

Please don’t hesitate to reach out to us at IOTG Solar for any questions or decisions concerning batteries and battery banks. We welcome the opportunity to engage in conversations, educate, and provide you with fundamental knowledge about incorporating an additional set of batteries into your new off-grid system.