Deye SUN-15K or SUN-20K: which three-phase inverter to choose
19 October 2026 · SK Partner s.r.o.
SUN-15K and SUN-20K-SG05LP3-EU-SM2 look the same, but differ in power, battery current and maximum photovoltaic power. A comparison based on the datasheet, selection by PV system size and peak demand, and how many SE-F16 batteries to pair with them.
The Deye SUN-15K-SG05LP3-EU-SM2 and SUN-20K-SG05LP3-EU-SM2 are three-phase hybrid inverters for 48V batteries from the SM2 series. They have the same enclosure, weight and interfaces — the difference lies in the power and in how much energy they can take in at once from the panels and from the battery.
Comparison based on the datasheet
| Parameter | SUN-15K | SUN-20K |
|---|---|---|
| Rated AC power | 15 kW | 20 kW |
| Max. photovoltaic power | 22,500 W | 30,000 W |
| Battery charging / discharging current | 280 A | 350 A |
| Rated AC current | 22.8/21.8 A | 30.4/29 A |
| MPPT trackers | 2 (160–650 V) | 2 (160–650 V) |
| Dimensions, weight | 456 × 750 × 268.5 mm, 50.6 kg | 456 × 750 × 268.5 mm, 50.6 kg |
| Parallel connection | up to 10 units | up to 10 units |
Both inverters have a fully unbalanced output — each phase can deliver up to 50% of the rated power — and support 6 time slots for charging and discharging as well as the connection of a diesel generator.
Which one to choose
- By size of the photovoltaic system: SUN-15K accepts up to 22.5 kW of panels, SUN-20K up to 30 kW. If you are planning a larger array, the choice is clear.
- By demand: SUN-15K delivers 15 kW continuously, SUN-20K 20 kW. With large loads running at the same time (heat pump, car charging, workshop), a reserve pays off.
- By battery: higher power only makes sense if the battery can take it in and deliver it — see below.
How many SE-F16 batteries
The Deye SE-F16-C battery (16 kWh) continuously accepts a charging current of up to 160 A and delivers a discharging current of up to 230 A. A single battery therefore cannot handle the full charging current of either inverter.
For SUN-15K (280 A) we recommend at least two batteries, for SUN-20K (350 A) two to three — only then does the inverter make use of its power both when charging and at night. The batteries are connected in parallel (up to 32 units).
Ready-made sets
We also offer both inverters as sets with one, two or three SE-F16 batteries (16, 32 and 48 kWh). A set works out cheaper than separate components and everything has been checked for mutual compatibility.
Frequently asked questions
Can the system be expanded later?
Yes. Up to 10 inverters and up to 32 SE-F16 batteries can be connected in parallel — we will verify the specific expansion against your configuration.
Do I need a three-phase connection for SUN-20K?
Yes, both inverters are three-phase (3L+N+PE, 230/400 V).
What is the difference compared with SUN-10K and SUN-12K?
The 10 and 12 kW inverters from the SG05LP3 series are smaller (35.2 kg), with a charging current of up to 210 and 240 A respectively — they suit ordinary family homes. SUN-15K and SUN-20K are for larger houses, farms and smaller businesses.
Where to buy
SUN-15K, SUN-20K, the SE-F16-C battery and ready-made sets are all in our range. After registration, companies see partner prices directly in the online shop.