APsystems (Altenergy Power System) ELS-5K

Battery inverter, ac-coupled battery inverter. 1 model, 5 kW AC at 240 V.

UL 1741 SBCEC listed · Jul 11, 2023

Rated AC power5 kW
CEC weighted efficiency94.0%

AC output (grid side)

APsystems (Altenergy Power System) datasheet · CEC Grid Support Inverter List (Oct 7, 2026)

Rated AC power5 kW
CEC-measured continuous output5.01 kW
Grid voltage240 V
Phasesplit-phase 120/240 V
AC voltage range211–264 V
Max continuous output current20.8 A

Efficiency

CEC Grid Support Inverter List (Oct 7, 2026) · APsystems (Altenergy Power System) datasheet · NLR SAM inverter library

CEC weighted efficiency94.0%
Peak efficiency96.5%
Night-time standby (tare)4.01 W
Power to start converting71.9 W

CEC weighted efficiency is measured by an accredited lab at six power levels and three DC voltages — the number to compare between inverters.

Grid & smart-inverter certification

CEC Grid Support Inverter List (Oct 7, 2026) · APsystems (Altenergy Power System) datasheet

UL 1741 SB (3rd ed.)Yes — CSA Group, certificate May 6, 2023
UL 1741 SA (SA8–SA13)Yes — CSA Group
Firmware tested (SA)V1.0.13
Volt-VAr with reactive power priority (SA13)Yes
Freq-Watt / Volt-Watt (SA14–15)Yes
Disable permit service / limit active power (SA17–18)Yes
CSIP (IEEE 2030.5) conformanceVia gateway during testing (Y*)
Monitor key data & scheduling (Rule 21 Phase 3)Yes (attested Jul 11, 2023)
CEC listedJul 11, 2023
Standards listed on the datasheetUL 1741, UL 1741 SA, UL 9540, CSA C22.2, FCC Part 15, CA Rule 21

UL 1741 SB is required for new interconnections in California (Rule 21) since 2026.

Monitoring & communication

APsystems (Altenergy Power System) datasheet

InterfacesEthernet, RS485, CAN

Size, weight & environment

APsystems (Altenergy Power System) datasheet

Dimensions (W × H × D)33.3 × 19.8 × 7.8 in
Weight66.1 lb (30 kg)
Enclosure ratingNEMA Type 4X
CoolingNatural convection (no fans)

Compare with similar 5 kW inverters

CEC Grid Support Inverter List (Oct 7, 2026) · building permits

Inverter	Power	CEC weighted eff.	DC test window	UL 1741 SB	Latest CEC	SoCal permits
APsystems (Altenergy Power System) ELS-xK	5 kW–5 kW	94.0%	52–60 V	Yes	2023	0
GoodWe GWxxxxA-BP	5 kW–9.6 kW	96.5%	200–495 V	Yes	2021	1
FOXESS AIO-AC1-x.x-US	3.8 kW–11.4 kW	97.0%	85–500 V	Yes	2025	—
APsystems (Altenergy Power System) ELS	6.61 kW–11.4 kW	94.0%	51–60 V	Yes	2024	—
Hoymiles HAS-x.xLV-USG1	3.8 kW–11.5 kW	94.0%	50–60 V	Yes	2024	—

Same type and grid voltage, power range covering this model; same fields from the same sources.

About APsystems (Altenergy Power System)

CEC Grid Support Inverter List (Oct 7, 2026)

ManufacturerAPsystems (Altenergy Power System)
Listed in CEC asAltenergy Power System Inc.
Websiteapsystems.com
Models on CEC lists101

Other series

ELS

Documents

manufacturer documents

PDF
4304405202 PCS ELS-5K-NA Datasheet REV1.4 2023-02-09-web
Datasheet · APsystems · Apr 2023

Questions & answers

How efficient is the APsystems (Altenergy Power System) ELS-xK?

The California Energy Commission lists a weighted efficiency of 94.0% for APsystems (Altenergy Power System) ELS-xK models, measured at six power levels and three DC voltages. The datasheet states a peak efficiency of 96.5%.

Is the APsystems (Altenergy Power System) ELS-xK certified to UL 1741 SB?

Yes — the CEC Grid Support Inverter List shows UL 1741 SB for all models.

Can the APsystems (Altenergy Power System) ELS-xK be used with a battery?

The CEC lists it as a ac-coupled battery inverter.

What is the ELS-5K’s DC input voltage range?

CEC tested it at 52–60 V DC.

Sources

California Energy Commission — Grid Support Inverter List (solar and battery inverters), data as of Oct 7, 2026. Manufacturer-reported, confirmed by CEC against certificates and test reports.
APsystems (Altenergy Power System) — datasheet 4304405202 PCS ELS-5K-NA Datasheet REV1.4 2023-02-09-web.
APsystems (Altenergy Power System) — document library on the manufacturer’s website (links above).
NLR (formerly NREL) — System Advisor Model CEC inverter library (version 2026.7.3).
Building permits — Southern California permit portals. Equipment matched from permit descriptions.