MK
Researched & reviewed by Maarten Kronberger
Published 2025-11-12 • Updated 2026-10-07 • SolarPowerGuide
Owned and used by the author
My verdict: 4.6 / 5
This Deye SUN-5K-SG01LP1-EU has been the heart of my home solar system for about three years, and since 13 June 2026 it has run my home
in KwaZulu-Natal completely off-grid. Everything below comes from living with it, plus Deye's published specifications.
My setup
I didn't buy my system in one go. It was built in stages over three years, and the inverter is the one component that has been there from the
start. Today it runs:
Inverter: Deye SUN-5K-SG01LP1-EU (single phase, 48 V low-voltage battery, two MPPTs).Panels: six JA Solar 550 W and four JA Solar 600 W (JAM72S40-600MR), about 5.7 kW in total, on an elevated structure above the tree line.Battery: a Dyness PowerBrick Plus (16.4 kWh). The system started on a 5 kWh Volta battery, which I later replaced. Why I switched .Monitoring: SolarmanPV, which logs production, consumption and battery state continuously.Household: the geyser runs on gas, which takes the biggest load in most South African homes off the inverter entirely.
How it has performed
Since going fully off-grid in June 2026, the inverter has carried the whole household. In the first eight days of off-grid telemetry, peak
production ranged from 1,158 W on a heavily overcast day to 3,794 W on a clear winter day, and the inverter handled all of it without complaint.
The battery's lowest charge in normal use was 22%, and winter sun brought it back to 66% by the same afternoon.
The one alarming moment in that period was a state-of-charge reading that dropped from 100% to 8% with no matching consumption. That turned out
to be the battery's BMS recalibrating after its first cycles, which is documented behaviour for LiFePO4 batteries, not an inverter fault.
See the full eight days of data .
What 5 kW can and can't run
A 5 kW inverter runs a typical South African home well, provided you don't switch every heavy appliance on at once. The rating is about what you
draw at the same moment, not what you use in a day. Deye rates this inverter to deliver twice its rated power for 10 seconds, which helps with
motor start-up surges from pumps and compressors.
In our house, the washing machine, tumble dryer, dishwasher, pool pump and borehole all run on solar. The trick is scheduling them for the sunny
part of the day rather than together.
Here is exactly how we schedule them .
Specifications
Rated AC output 5,000 W, single phase Off-grid peak power 2 times rated power for 10 seconds Max PV input power 6,500 W Max PV input voltage 500 V MPPT trackers 2 Battery voltage range 40 to 60 V (48 V lead-acid or lithium) Max battery charge/discharge 120 A Max efficiency 97.6% Time-of-use programming 6 charge/discharge periods Generator input Supported Enclosure IP65
From Deye's published specifications for the SUN-5K-SG01LP1 range. Regional variants can differ slightly, so check the label on the unit you buy.
Pros and Cons
Pros
Runs a whole off-grid household when heavy loads are scheduled sensibly
6.5 kW of PV input leaves room to add panels beyond the 5 kW output
Twice-rated surge for 10 seconds copes with pump and compressor start-up
Six time-of-use periods and generator support
Widely installed in South Africa, so installers know it well
Cons
5 kW is a hard ceiling, so heavy loads must be staggered
The monitoring app is functional but less polished than Sunsynk's
After-sales support from Deye has sometimes been lacking in KZN, so buy through an installer who will handle warranty claims
Who it suits
A typical South African home that wants solid backup or, with a large enough battery and some load discipline, full off-grid independence.
If you regularly run several heavy appliances at the same time, or you're planning a big array, look at a 6 kW or 8 kW model instead.
Compare it with the Sunsynk , which in my experience matches the
equivalent Deye in every spec except the app, at a higher price.
My Verdict 4.6 / 5
After three years, and months of running my home fully off-grid, it has done everything I've asked of it. The 5 kW ceiling means planning your heavy loads, and Deye's local support could be better, but for value and reliability it's hard to beat.
