What is the Deye SUN-20K-SG05LP3-EU-SM2?
- Type: 3-phase hybrid inverter, 20 kW rated output (max 22 kVA) — battery-ready, keeps the power on during outages
- PV input: up to 40 kW via 2 MPPTs (2+2 strings), MPPT voltage range 160-650V
- Battery: 48V low-voltage system (40-60V), up to 350A charge/discharge, Lithium-ion or Lead-acid
- Build: IP65, outdoor-mountable, up to 97.6% efficiency, 5/10-year manufacturer warranty
- Best for: large villas, 3-phase businesses that need battery backup, or areas with frequent outages
In any solar system that needs battery backup, the heart of the setup is the hybrid inverter — and the Deye SUN-20K-SG05LP3-EU-SM2 is the 20 kW three-phase model our team has chosen for many villa and business projects. This page summarises the key specs straight from the manufacturer's datasheet and explains what each number means in real-world use. (Not sure how a hybrid system differs from on-grid? Start with our guide: Hybrid solar with battery backup in Phuket)
What it is: a 3-phase hybrid — battery-ready, power stays on
The SUN-20K is a hybrid inverter, meaning one unit does it all: it converts power from the solar panels for use in the house, exports the surplus to the grid, charges it into the batteries — and when the grid goes down, the system switches over and keeps feeding your connected loads from the battery and the panels. That's unlike an ordinary on-grid inverter, which has to shut down whenever the grid does.
What makes this model right for large homes and businesses is that it's a 3-phase system (3L+N+PE, 220/380V or 230/400V), connecting directly to a 3-phase meter — and per the datasheet it supports 100% unbalanced loads, with each phase able to deliver up to 50% of rated power. That matches real buildings, where the load is never spread evenly across phases.
Datasheet highlights
- Room to grow on PV: Max. PV Access Power of up to 40,000W through 2 independent MPPTs (2 strings per side) — design for a two-aspect roof, or leave headroom to add panels later
- Serious battery current: up to 350A charge/discharge on the 48V battery system, supports multiple battery banks in parallel, and talks to lithium battery BMS automatically (Self-adaption to BMS)
- Scales up: parallel up to 10 units, in both on-grid and off-grid mode — start with one unit and grow into a large system later
- Retrofits existing systems: AC Couple support lets it bolt onto an existing on-grid installation to add battery backup
- Works with generators: supports storing energy from a diesel generator into the batteries — ideal for businesses that already run backup gensets
- 6 programmable battery windows: schedule up to 6 charge/discharge time windows per day — charge when power is cheap, discharge when it's expensive
- Peak loads during outages: off-grid mode delivers 2x rated power for 10 seconds, covering the start-up surge of water pumps and air conditioners
- Full protection suite: built-in protections including DC reverse polarity, output overcurrent/overvoltage, residual current detection (RCD), Island Protection, and Type II surge protection on both the DC and AC sides
- Monitoring options: supports WIFI/GPRS/Bluetooth/4G/LAN (optional) — track your production in the app
Key spec table (SUN-20K-SG05LP3-EU-SM2)
| Item | Datasheet value |
|---|---|
| Rated AC output power | 20,000 W (max 22,000 VA) |
| AC output current | Rated 29 A / max 31.9 A |
| Grid type | 3-phase 3L+N+PE, 220/380V or 230/400V, 50/60 Hz |
| Max PV access power | 40,000 W (Max. PV Input Power 32,000 W) |
| MPPT | 2 (2+2 strings), voltage range 160-650V, max PV voltage 800V |
| PV current | Max operating 36+36 A / max short-circuit 54+54 A |
| Battery | Lithium-ion or Lead-acid, 40-60V (48V system) |
| Max battery charge/discharge current | 350 A / 350 A |
| Off-grid peak power | 2x rated power for 10 seconds |
| Efficiency | Max 97.6% / Euro 97.0% / MPPT >99% |
| Parallel operation | Up to 10 units (on-grid and off-grid) |
| Ingress protection | IP65 (outdoor installation possible) |
| Operating temperature | -40 to +60°C (derating above 45°C) |
| Cooling / noise | Intelligent Air Cooling / <60 dB |
| Dimensions / weight | 456×750×268.5 mm / 50.6 kg |
| Communication | RS485/RS232/CAN · monitoring via GPRS/WIFI/Bluetooth/4G/LAN (optional) |
| Warranty | 5/10 years depending on installation region (per the manufacturer's Warranty Policy) |
Note: all figures are taken directly from the datasheet of Ningbo Deye Inverter Technology Co., Ltd. The actual system design (panels per string, cable sizing, breakers) must be calculated for each individual site.
Installed in Phuket — by our own crew
This page isn't written from paper alone — a Deye Hybrid 20kW system with batteries is exactly what our own crew has installed here in Phuket. We do every step ourselves: crimping the DC (MC4) connectors, running cables into the unit, voltage-testing every point before going live, and finishing the MDB control cabinet neatly with a full set of breakers and surge protection. The photos below are the real site, from installation through to handover.
See the full photo set, along with our other work, on our projects page
Why Deye Hybrid suits Phuket
- Brownouts and outages in monsoon season: Phuket gets storms and localised outages through the rainy season — a hybrid system with batteries switches to backup mode and keeps feeding your connected loads from the battery, with no waiting for the grid to come back
- Batteries can grow with you: the 48V battery system at up to 350A supports multiple banks in parallel — start with a capacity that fits your budget and expand later (read more: is battery storage worth it?)
- 3-phase matches villas and businesses: most large villas and businesses in Phuket run on 3-phase meters — this is a true 3-phase unit with 100% unbalanced load support, right for homes with pool pumps and multiple air conditioners (design guidance: solar for pool villas in Phuket)
- Our crew is based in Phuket: aftercare, checkups and on-site fixes get scheduled for real — no waiting for a team from another province
For the full picture on battery backup for villa owners, read our guide: Hybrid Solar with Battery Backup in Phuket
Who it's for
- Villas and large homes on 3-phase power: 20 kW covers multiple air conditioners, pool pumps and a fully equipped home — with battery backup so the power never skips a beat
- Businesses where an outage costs money: restaurants, clinics, minimarts or offices that need continuous power — off-grid mode picks up from the battery the moment the grid drops
- Areas with frequent brownouts or outages: store daytime solar for the evening or for outages, with 6 programmable charge/discharge windows you set yourself
- Businesses that already own a generator: this model supports storing energy from a diesel genset into the batteries, working together as a multi-layer backup system
- On-grid owners who want to add batteries: use its AC Couple capability to bolt onto the existing system with nothing torn out
We install this model ourselves — see the site photos on our projects page, including a Deye Hybrid installation with batteries recently handed over to the customer
Want to compare with other brands before deciding? See our Thai-language guide to popular inverter brands in Thailand, or browse all the equipment we install
Summary
The Deye SUN-20K-SG05LP3-EU-SM2 is a do-it-all 3-phase hybrid inverter for large homes and businesses that want lower bills and backup power in one system. Its strengths: up to 40 kW of PV, high 350A battery current, parallel expansion up to 10 units, and an IP65 weather-rated body. How many panels and batteries your system needs depends on how you actually use power — contact our team for a free site survey and system design, no obligation
Download the datasheet (PDF) — the manufacturer's full specification document