Solis Single Phase 5kW Low Voltage AC-Coupled Inverters

The Solis S6 5 kW AC-coupled inverter (S6-EA1P5K-L) adds a 40–60 V lithium battery to a home that already has solar. It has no PV inputs of its own: it joins the house wiring on the AC side, so the existing panels and grid-tied inverter carry on as they are, while it moves up to 105 A in or out of the battery.

Surplus that would otherwise be exported goes into the battery and is used in the house later, six time-of-use windows let it charge from a cheap overnight rate as well, and peak shaving draws on the battery only when grid import climbs past a level you set. Being a separate unit, it suits a system whose inverter is staying put rather than one due for replacement.

The 5 kW in figures

Adding a battery to solar you already have

Solis built the EA1P range to turn an existing on-grid system into a hybrid one. In Self-Use mode the panels serve the home first and the surplus charges the battery; once it is full, the rest is exported as before. Feed-in Priority swaps that second step, exporting up to the set quota and storing only what is left over, so it is the wrong mode for a site with export held at zero. Peak-shaving discharges the battery only while grid import is above the limit you choose.

Within those modes, Time of Use gives six charge and six discharge windows, each at a current you set. With Allow Grid Charging on, the inverter makes up from the grid whatever the panels cannot supply during a charge window, which is how an overnight tariff fills the battery. Between times it drops into a low-power standby, and real-time battery monitoring, remote firmware upgrades and a battery-healing function look after the battery over its life.

Batteries it works with

The starting point is a 40–60 V lithium battery that talks to the inverter over CAN. The setup menu names Pylontech, BYD, Dyness and PureDrive LV models, and has general settings for 48 V and 51.2 V lithium batteries without communication. Solis's compatible battery list for the S6-EA1P(3.6-6)K-L range (V1.5, March 2024) runs to dozens of brands, among them BYD's Battery-Box Premium LVS and LVL, Pylontech's UP5000, US2000B and US3000A, Dyness's DL Series and PowerDepot H5B, Fox's LV5200 and LG's RESU range.

Solis attaches two conditions. Compatibility varies by market, so confirm a pairing with Solis for a UK install, and fitting a battery that is not compatible voids the inverter's warranty. Check the battery's own current rating too: the inverter charges and discharges at up to 105 A, and a battery rated lower sets the limit. A single Dyness DL5.0C Pro, for example, charges at up to 75 A and discharges at up to 100 A.

Where it goes and how it is wired

It hangs on its backplate truly vertical, within 5° either way, at least 250 mm clear of other equipment and with its bottom edge 800 mm or more above the ground. Solis's ideal spot is a north-facing wall under an eave, out of direct sun, which makes the output derate, and out of direct rain and snow, despite the IP66 rating. The heat sink can reach 75 °C, so the wall has to be non-combustible and able to carry four times the unit's weight; keep it 3 m from anything flammable and out of rooms people spend long stretches in, because it can be noticeably loud.

The grid side takes 2.5–6 mm² cable, 6 mm² past 20 m, behind a 40 A protective device. On the battery side, Solis recommends a DC breaker between battery and inverter to prevent arcing, rated 160 A for this size, and the four R-terminals in the box are for the battery leads. The external earth conductor should be 4 mm² or more.

In the box

DNO approval

Order alongside

• Solis Eastron SDM120CT single-phase meter

  The optional meter, with its own external CT, wired to the inverter's Meter port over RS485. It is the part for a meter position too far away for the CT lead to reach.

• Dyness DL5.0C Pro 5.12 kWh battery

  From the Dyness DL Series named on Solis's list for this range. One module charges at up to 75 A, under the inverter's 105 A.

• Warranty extension to 10 years

  Five more years on the standard five. Put the inverter's serial number in the order notes; the certificate arrives from Solis in about 6 to 8 weeks.

• Warranty extension to 20 years

  Fifteen years on top of the standard five, taking the EA1P's cover to 20 years.