Deye SUN-5K-SG03LP1-EU (5 kW) - single-phase hybrid inverter

Who these 5 kW suit, and when they stop being enough

Five kilowatts of continuous power on a single-phase supply is the most common size for a detached house consuming 10 to 15 kWh a day, where heating runs on gas or solid fuel and electricity serves the fridge, pumps, lighting, appliances and a couple of air conditioners. An inverter of this class covers a typical outage completely: with storage attached, the house notices no difference between grid and no grid as long as total load stays within 5 kW. It also works well commercially — a small shop with two refrigerated cabinets, a coffee bar, an office or a workshop with hand tools, where continuity matters more than raw power. The limit shows up wherever electric heating is involved: a 2 kW resistive water heater together with a washing machine and an induction hob already exceeds the rating, and the system will trip at the least convenient moment. A three-phase supply is outside its scope — for that the catalogue offers the LP3 family, such as the SUN-10K-SG04LP3-EU (item 2061) — and spreading a single-phase inverter across three phases is not possible.

Two independent MPPTs: for a roof with two planes

The input side carries two independent MPPTs with one string each and an operating current of 11 A per tracker, and this is the key practical difference from the smaller single-tracker models. Two MPPTs mean the eastern and western roof planes can be wired separately, so shading or lower irradiance on one does not drag the other down — on a real two-plane roof that translates into a visibly higher daily yield. The tracker window spans 125 to 425 V against a 500 V maximum input and a 150 V start-up threshold, so a string of nine to eleven modules sits comfortably in range and the inverter wakes up early in the morning thanks to that low 125 V edge. Total array power is up to 6500 W, some thirty per cent above the inverter rating: this DC oversizing is deliberate, because it is what carries winter and overcast days when panels deliver a third of their nameplate. Tracking efficiency is quoted at 99.9 %, so losses in the search for the maximum power point barely affect the result; strings are best calculated close to the 370 V rated PV voltage, where conversion efficiency is highest.

A 48 V battery bus with 120 A — what it means in practice

The 48 V bus with its 40 to 60 V working range opens access to the entire lithium range in this catalogue: the SE-F5 (item 1944), the SE-G5.1 (item 1947), the RW-F10.2 (item 1930) and other 51.2 V modules connect without adapters or extra control boxes. Maximum charge and discharge current is 120 A, roughly 6 kW at 51.2 V, which is more than the inverter itself can convert — the bottleneck is the inverter rather than the battery, and for a system that is the more comfortable arrangement. A single 5.12 kWh module already provides some 4 kWh of usable energy and covers the evening peak plus a few hours of outage, but overnight autonomy for a house with pumps and air conditioning realistically calls for two or three modules. Lead-acid banks in AGM and GEL form are supported too, which helps when batteries are already on site, yet for daily cycling lithium wins on both service life and depth of discharge by a margin that pays back within a few years. The BMS link runs over RS485 or CAN and is what gives the inverter an accurate state of charge: without that exchange the system works from voltage alone and inevitably either undercharges the battery or discharges it deeper than it should.

A 10 000 W ten-second peak: why the double margin matters

Rated output is 5000 W, apparent power 5500 W, and in island mode the inverter holds 10 000 W for ten seconds — exactly double the headroom for inrush currents. That is a working parameter rather than a marketing line: a borehole pump, an air conditioning compressor, a circular saw or an older washing machine draw three to five times their nameplate figure at start-up, and without such a reserve the inverter would trip on overload every time. At 230 V the rated output current is about 21 A, which is the ceiling for continuous operation, while grid pass-through is rated at 35 A — as long as mains power is present the house draws through the inverter almost without restriction. Total harmonic distortion stays below 3 %, and below 1.5 % on linear loads: the waveform is clean enough for gas boilers with electronic controls, variable-speed circulation pumps and audio equipment. The limitation of that ten-second peak is worth understanding: it rescues start-ups, but if the load sits above 5 kW for minutes at a time the inverter will go into protection, and that duty needs a larger model.

Cooling, efficiency and mounting

Peak efficiency is 97.6 % and the European figure 97 %, meaning roughly 150 W turns into heat for every 5 kW passed through, and that heat has to be removed. This model uses forced cooling: the fan lets it hold full power in hot weather, but it is a moving part worth blowing out from dust once a year, particularly in a boiler room or a workshop. The 420 by 680 by 233 mm enclosure weighs 32 kg, so wall mounting takes two people and solid masonry — that mass cannot hang on plasterboard. The IP65 rating formally permits outdoor installation, yet a technical room is the wiser choice: the unit works from -25 to +60 °C, but direct summer sun on the housing raises heatsink temperature and forces the electronics to derate. Noise is quoted below 30 dB, which is quiet for a hallway, though at full load the fan is noticeably more audible than on passively cooled models.

Behaviour during an outage and the everyday logic of operation

When the grid fails the inverter switches to battery and panels automatically, and for the household it looks like a brief flicker rather than a blackout. Energy routing is configurable: during the day priority can go to self-consumption, to battery charging or to exporting the surplus — under Ukrainian conditions the usual choice is house first, battery second, so storage is always full before the evening outage window. There is also a scheduled grid-charging mode: when outages are predictable the inverter tops up from the mains while it is available, instead of leaving the house with a half-empty battery. All of this is visible in the mobile app through the communication module, and that is where daily generation and discharge curves are best examined — without them, setting priorities becomes guesswork. One point for planning: output during an outage is capped at 5 kW regardless of how many panels and batteries you have, so critical loads belong on a separate circuit and the water heater should not run together with the washing machine.

How it differs from its neighbours in this catalogue

Its closest relative is the SUN-6K-SG05LP1-EU (item 2053): same enclosure, same weight, but 6 kW instead of 5, an array of up to 7800 W, 13 A trackers and 40 A of grid transit, so the step up is justified once loads already press against five kilowatts. If a water heater, an air conditioner and a workshop are all planned at once, it is more sensible to take the SUN-8K-SG01LP1-EU (item 2047) with its 190 A battery current or the SUN-10K-SG02LP1-EU-AM3 (item 2059) with three MPPTs straight away. The smaller SUN-3K-SG04LP1-EU (item 2048) is cheaper as a system but runs a 24 V bus that accepts only 24 V modules — a fundamentally different architecture, not merely fewer kilowatts. Most importantly, do not confuse this unit with the grid-tie SUN-5K-G (item 2086), also rated 5 kW and half the weight: it has no battery input and shuts down when the grid fails, so it serves to cut bills, not to provide backup.

Send us your load list and the hours of autonomy you want, and we will tell you whether 5 kW is enough and how many battery modules that corresponds to.