RAI-3K-48ES-5G storage inverter

RAI-3K-48ES-5G is a Solis AC-coupled battery inverter for retrofitting storage to a grid-tied solar installation. It has no direct solar-string input. Solar generation reaches it through the property’s AC wiring after conversion by the existing solar inverter.

Current position

Solis retains an RAI installation video, identifies the model in older technical guidance and includes it in the product selector on its UK warranty page. It was not listed in the current UK AC-coupled catalogue reviewed on 23 July 2026, which instead presents S5-EA1P3K-L and S6-EA1P(3.6-6)K-L. Current new UK supply is therefore unconfirmed rather than assumed from retained support material.

That position does not affect the identity of installed units. The rating label and serial number establish whether the unit is the 5G RAI model and which manual and warranty record apply.

Installed-system configuration

The model name encodes a 3 kW single-phase inverter for a 48 V battery class. Battery compatibility still depends on the exact battery model, communications protocol and firmware. The approved list applicable when the system was commissioned is more useful than a generic statement that a battery is nominally 48 V.

An AC-coupled arrangement has a separate solar inverter and battery inverter. Export limitation, metering direction and the location of current transformers therefore need to reflect both power paths. Any backup function also depends on the installed switching and protected-load circuits, not the RAI label alone.

The current UK warranty document applies only to products produced from 1 July 2025. An older RAI unit keeps the terms supplied with it, so the invoice, commissioning record and warranty certificate should be retained.

Related entries

• Solis
• Solis AC-coupled inverter
• AC-coupled battery architecture
• Export limitation with batteries