Why do parallel hybrid inverters appear to share the load unevenly?

What you will see

• One inverter shows higher power than the other.
• One unit reports overload while the other appears lightly loaded.
• A parallel-system warning appears after an update or replacement.
• The difference becomes noticeable during load-shedding.

Why it happens

Approved parallel operation depends on compatible equipment, correct configuration and working communication. Solis, for example, specifies model matching and firmware consistency for the parallel arrangement described in its guidance. The requirements must be checked for the actual product family.

The same guidance assigns separate PV inputs to individual units. Different solar-input readings therefore do not automatically establish unequal backup-load sharing.

Ask which operating state was active when the readings were taken. Comparing one inverter’s PV power with another’s AC output, or screenshots captured at different times, can produce a misleading conclusion.

If a genuine difference persists in the same output measurement, the installer should review the approved design, each unit’s status, battery arrangement and commissioning records. An inverter shown as online in an app is not, by itself, proof that it is participating correctly in the parallel system.

Diagram

Compare like with like

Misleading comparison

Unit A solar input against unit B backup output, or screenshots taken minutes apart.

Useful comparison

The same output reading from both units, captured at the same moment, with the operating state noted.

Record for each unit:

Output readingTimestampGrid or backupWarningsRunning appliances

Separate PV inputs mean different solar readings are expected. A lasting gap in the same output reading needs a review.

What you can check yourself

• Capture both units’ output readings with matching timestamps and visible screen labels.
• Record whether grid electricity was present or the system was supplying backup.
• Save parallel, battery and overload warnings from each inverter.
• Note whether the difference began after replacement, expansion or a firmware update.
• Collect the installed inverter and battery model list from handover documents.
• Include the system-level screen as well as each unit’s screen. Tell us which appliances were operating when the difference appeared, especially any large motor or compressor.

What not to do

• Do not change primary/secondary roles, communication switches or parallel settings. Do not disconnect a unit to see whether the other takes over, and never join inverter outputs without an approved design.

When to call us

• Arrange a review if one unit repeatedly overloads, a parallel warning persists, or backup performance changed after work on the system. The goal is to verify participation and the intended sharing behaviour before replacing equipment.

Parallel systems in Faisalabad and Lahore

Many larger homes and businesses in Faisalabad and Lahore run two hybrid inverters in parallel. Send our team simultaneous screenshots from both units so we can compare like with like.

Send us

All inverter models, the battery arrangement, simultaneous screenshots, warning details, recent changes, and your city and area.