Products from the aj inverter series
The aj 275-400 has been discontinued
aj 275-400, simple and straightforward solution for standalone applications
high-end Swiss-made inverter
- This picture depicts a standalone application in Micronesia (Oceania).
aj, Swiss simplicity and durability for your energy needs
The aj series pure sine wave inverters convert battery voltage into high-quality 230/120Vac which can be used for all electrical appliances. Designed to meet industrial and domestic needs, the aj is the optimal solution for standalone applications, fulfilling the highest requirements in terms of comfort, safety and reliability. Manufactured since 1998 in Switzerland with a 10-year warranty and delivered with AC and battery cables, the aj is a true “plug and forget solution”.
aj, Swiss simplicity and durability for your energy needs
The aj series pure sine wave inverters convert battery voltage into high-quality 230/120Vac which can be used for all electrical appliances. Designed to meet industrial and domestic needs, the aj is the optimal solution for standalone applications, fulfilling the highest requirements in terms of comfort, safety and reliability. Manufactured since 1998 in Switzerland with a 10-year warranty and delivered with AC and battery cables, the aj is a true “plug and forget solution”.
High overload capabilities
> 2 times the nominal power
Plug and play
Supplied with battery and AC cables, ready to power your application
10 years warranty
Optional integrated solar charger
The aj models can be equipped with an integrated PWM controller for an all-in-one solar system.
High overload capabilities
> 2 times the nominal power
Plug and play
Supplied with battery and AC cables, ready to power your application
10 years warranty
Optional integrated solar charger
The aj models can be equipped with an integrated PWM controller for an all-in-one solar system.
Designed for a wide range of uses
Flexibility of use for your applications
offgrid application
solar home systems
mobile application
on board power
What customers think
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Swiss made 
Proudly designed, assembled, and tested in Switzerland, ensuring the highest standards of quality and reliability that Studer Innotec is known for.
Every unit undergoes strict controls to ensure performance, long-term durability, and seamless operation in the most demanding environments.
With Swiss made excellence, you can trust the aj to deliver reliability for years to come.
Swiss made
Swiss made
Proudly designed, assembled, and tested in Switzerland, ensuring the highest standards of quality and reliability that Studer Innotec is known for.
Every unit undergoes strict controls to ensure performance, long-term durability, and seamless operation in the most demanding environments.
With Swiss made excellence, you can trust the aj to deliver reliability for years to come.
Digital regulation and control by microprocessor
A whole range with plenty of options
The aj series covers a complete range of sine wave inverters, from 800 VA to 2400 VA solutions for offgrid applications and battery voltages 12 and 24 V.
Rugged, efficient and easy to use with the option of adding an integrated PWM regulator. Every aj inverter is built to deliver reliable energy in all conditions.
Ideally suited for rural electrification and recognised by NGOs for this purpose
The aj inverter is recognised and used by NGOs and governments, such as USAID, the Ministry of Health/Education of Uganda, the Ministry of Electricity and Renewable Energy of Peru, the European Commission’s Directorate-General for Development and Cooperation – EuropeAid.
With more than 25 years on the market, it is known for its reliability in the field of rural electrification.
Adjustable standby level for lower power consumption
In offgrid every watt counts. The standby is an energy saving system which turns off the inverter intermittently when no consumer is detected. This function is available for small units (aj 275-400) only with the integrated solar regulator.
Worldwide compatibility
The entire aj series is compatible with 230V/50Hz and 120V/60Hz.
Battery compatibility
The aj is compatible with all 12/24/48 V (depending on the model chosen) lead/AGM battery and equivalent chemistries.
Thanks to precise charge control and advanced management algorithms, your batteries operate efficiently, reliably, and for the long run.
Adaptative management of batteries
With more than 3 decades of expertise in offgrid energy management, we have perfected battery optimisation to ensure a long-lasting performance. The aj features our Battery Lifetime Optimizer (BLO), which intelligently adapts charge cycles to preserve battery health and extend its lifespan.
Options & accessories
version s
integrated solar charger
version 01
AC out 120Vac & 60Hz
version 02
AC out 120Vac & 50Hz
version 03
AC out 220Vac & 60Hz
version RCM01
start up when contact closed
version RCM02
start up when voltage present
version RCM03
start up when contact open
Options & accessories
version s
integrated solar charger
version 01
AC out 120Vac & 60Hz
version 02
AC out 120Vac & 50Hz
version 03
AC out 220Vac & 60Hz
version RCM01
start up when contact closed
version RCM02
start up when voltage present
version RCM03
start up when contact open
Technical specifications
aj 275-400 inverters
In case of technical data change, this bloc below needs to update, it is use for mobile display of technical data
Inverter
| Nominal battery voltage (Input range) | 12 Vdc (10.5 – 16 Vdc) |
| Power 30 min. 25°C | 275 VA |
| Continuous power 25°C | 200 VA |
| Power 5 min. 25°C | 350 VA |
| Power 5 sec. 25°C | 450 VA |
| Asymmetric load | 150 VA |
| Max. efficiency (%) | 93% |
| Cos φ max. | 0.1 – 1 up to 200 VA |
| Detection of the load | 2 W only with the solar option -S |
| Short-circuit current AC 2 sec. | 2.3 Aac (4.6 Aac*) |
| Output voltage | Sine wave 230 Vac (120 Vac*) ±5 % |
| Frequency | 50 Hz (60 Hz*) ± 0.05 % (crystal controlled) |
| Consumption Stand-by / ON no load | 0.3 W**/ 2.4 W |
| Reverse polarity protection as internal fuse | 60 A |
General data
| Weight | 2.4 kg |
| Dimensions h/w/l [mm] | 142/163/84 mm |
| Conformity | low voltage directive (LVD) 2014/35/EU: EN/IEC 62109-1, 62109-2, 62477-1, electromagnetic compliance (EMC) directive 2014/30/EU: EN/IEC 61000-3-3, 61000-6-2, 61000-6-4, 62040-2 |
Ingress protection of enclosures IP30 | Operating temperature range -20 to 50°C | Relative humidity 95 % (non condensing) | Ventilation forced from 45°C ± 5°C | Length cables (battery/AC out) 1.2 m / 1 m | Acoustic level < 45 dB (with ventilation) | Approximate correction of Pnom -1.5% / °C from + 25°C | Recommended battery capacity > 5 x Pnom/Unom (recommended value in Ah)
Options
| Solar regulator | Voltage max. 25 Vdc |
| Current max. 10 Adc | |
| Principle: Floating 3 stages (I/U/UO) | |
| Absorption voltage: 14.4 Vdc | |
| Floating voltage: 13.6 Vdc | |
| Remote control (RCM-01/-02/-03) | ✔ |
Inverter
| Nominal battery voltage (Input range) | 24 Vdc (21 – 32 Vdc) |
| Power 30 min. 25°C | 350 VA |
| Continuous power 25°C | 300 VA |
| Power 5 min. 25°C | 500 VA |
| Power 5 sec. 25°C | 650 VA |
| Asymmetric load | 150 VA |
| Max. efficiency (%) | 94% |
| Cos φ max. | 0.1 – 1 up to 300 VA |
| Detection of the load | 2 W only with the solar option -S |
| Short-circuit current AC 2 sec. | 3.2 Aac (6.4 Aac*) |
| Output voltage | Sine wave 230 Vac (120 Vac*) ±5 % |
| Frequency | 50 Hz (60 Hz*) ± 0.05 % (crystal controlled) |
| Consumption Stand-by / ON no load | 0.5 W**/ 3.5 W |
| Reverse polarity protection as internal fuse | 40 A |
General data
| Weight | 2.6 kg |
| Dimensions h/w/l [mm] | 142/163/84 mm |
| Conformity | low voltage directive (LVD) 2014/35/EU: EN/IEC 62109-1, 62109-2, 62477-1, electromagnetic compliance (EMC) directive 2014/30/EU: EN/IEC 61000-3-3, 61000-6-2, 61000-6-4, 62040-2 |
Ingress protection of enclosures IP30 | Operating temperature range -20 to 50°C | Relative humidity 95 % (non condensing) | Ventilation forced from 45°C ± 5°C | Length cables (battery/AC out) 1.2 m / 1 m | Acoustic level < 45 dB (with ventilation) | Approximate correction of Pnom -1.5% / °C from + 25°C | Recommended battery capacity > 5 x Pnom/Unom (recommended value in Ah)
Options
| Solar regulator | Voltage max. 45 Vdc |
| Current max. 10 Adc | |
| Principle: Floating 3 stages (I/U/UO) | |
| Absorption voltage: 28.8 Vdc | |
| Floating voltage: 27.2 Vdc | |
| Remote control (RCM-01/-02/-03) | ✔ |
Inverter
| Nominal battery voltage (Input range) | 48 Vdc (42 – 60 Vdc) |
| Power 30 min. 25°C | 400 VA |
| Continuous power 25°C | 300 VA |
| Power 5 min. 25°C | 600 VA |
| Power 5 sec. 25°C | 1000 VA |
| Asymmetric load | 200 VA |
| Max. efficiency (%) | 94% |
| Cos φ max. | 0.1 – 1 up to 300 VA |
| Detection of the load | 2 W only with the solar option -S |
| Short-circuit current AC 2 sec. | 4.6 Aac (9.2 Aac*) |
| Output voltage | Sine wave 230 Vac (120 Vac*) ±5 % |
| Frequency | 50 Hz (60 Hz*) ± 0.05 % (crystal controlled) |
| Consumption Stand-by / ON no load | 1.1 W**/ 5.2 W |
| Reverse polarity protection as internal fuse | 25 A |
General data
| Weight | 2.6 kg |
| Dimensions h/w/l [mm] | 142/163/84 mm |
| Conformity | low voltage directive (LVD) 2014/35/EU: EN/IEC 62109-1, 62109-2, 62477-1, electromagnetic compliance (EMC) directive 2014/30/EU: EN/IEC 61000-3-3, 61000-6-2, 61000-6-4, 62040-2 |
Ingress protection of enclosures IP30 | Operating temperature range -20 to 50°C | Relative humidity 95 % (non condensing) | Ventilation forced from 45°C ± 5°C | Length cables (battery/AC out) 1.2 m / 1 m | Acoustic level < 45 dB (with ventilation) | Approximate correction of Pnom -1.5% / °C from + 25°C | Recommended battery capacity > 5 x Pnom/Unom (recommended value in Ah)
Options
| Solar regulator | Voltage max. 90 Vdc |
| Current max. 10 Adc | |
| Principle: Floating 3 stages (I/U/UO) | |
| Absorption voltage: 57.6 Vdc | |
| Floating voltage: 54.4 Vdc | |
| Remote control (RCM-01/-02/-03) | ✔ |
In case of technical data change, this bloc below needs to update, it is use for pc and tablets display of technical data
Inverter
| Nominal battery voltage (Input range) | 12 Vdc (10.5 – 16 Vdc) |
| Power 30 min. 25°C | 275 VA |
| Continuous power 25°C | 200 VA |
| Power 5 min. 25°C | 350 VA |
| Power 5 sec. 25°C | 450 VA |
| Asymmetric load | 150 VA |
| Max. efficiency (%) | 93% |
| Cos φ max. | 0.1 – 1 up to 200 VA |
| Detection of the load | 2 W only with the solar option -S |
| Short-circuit current AC 2 sec. | 2.3 Aac (4.6 Aac*) |
| Output voltage | Sine wave 230 Vac (120 Vac*) ±5 % |
| Frequency | 50 Hz (60 Hz*) ± 0.05 % (crystal controlled) |
| Consumption Stand-by / ON no load | 0.3 W**/ 2.4 W |
| Reverse polarity protection as internal fuse | 60 A |
General data
| Weight | 2.4 kg |
| Dimensions h/w/l [mm] | 142/163/84 mm |
| Conformity | low voltage directive (LVD) 2014/35/EU: EN/IEC 62109-1, 62109-2, 62477-1, electromagnetic compliance (EMC) directive 2014/30/EU: EN/IEC 61000-3-3, 61000-6-2, 61000-6-4, 62040-2 |
Ingress protection of enclosures IP30 | Operating temperature range -20 to 50°C | Relative humidity 95 % (non condensing) | Ventilation forced from 45°C ± 5°C | Length cables (battery/AC out) 1.2 m / 1 m | Acoustic level < 45 dB (with ventilation) | Approximate correction of Pnom -1.5% / °C from + 25°C | Recommended battery capacity > 5 x Pnom/Unom (recommended value in Ah)
Options
| Solar regulator | Voltage max. 25 Vdc |
| Current max. 10 Adc | |
| Principle: Floating 3 stages (I/U/UO) | |
| Absorption voltage: 14.4 Vdc | |
| Floating voltage: 13.6 Vdc | |
| Remote control (RCM-01/-02/-03) | ✔ |
Inverter
| Nominal battery voltage (Input range) | 24 Vdc (21 – 32 Vdc) |
| Power 30 min. 25°C | 350 VA |
| Continuous power 25°C | 300 VA |
| Power 5 min. 25°C | 500 VA |
| Power 5 sec. 25°C | 650 VA |
| Asymmetric load | 150 VA |
| Max. efficiency (%) | 94% |
| Cos φ max. | 0.1 – 1 up to 300 VA |
| Detection of the load | 2 W only with the solar option -S |
| Short-circuit current AC 2 sec. | 3.2 Aac (6.4 Aac*) |
| Output voltage | Sine wave 230 Vac (120 Vac*) ±5 % |
| Frequency | 50 Hz (60 Hz*) ± 0.05 % (crystal controlled) |
| Consumption Stand-by / ON no load | 0.5 W**/ 3.5 W |
| Reverse polarity protection as internal fuse | 40 A |
General data
| Weight | 2.6 kg |
| Dimensions h/w/l [mm] | 142/163/84 mm |
| Conformity | low voltage directive (LVD) 2014/35/EU: EN/IEC 62109-1, 62109-2, 62477-1, electromagnetic compliance (EMC) directive 2014/30/EU: EN/IEC 61000-3-3, 61000-6-2, 61000-6-4, 62040-2 |
Ingress protection of enclosures IP30 | Operating temperature range -20 to 50°C | Relative humidity 95 % (non condensing) | Ventilation forced from 45°C ± 5°C | Length cables (battery/AC out) 1.2 m / 1 m | Acoustic level < 45 dB (with ventilation) | Approximate correction of Pnom -1.5% / °C from + 25°C | Recommended battery capacity > 5 x Pnom/Unom (recommended value in Ah)
Options
| Solar regulator | Voltage max. 45 Vdc |
| Current max. 10 Adc | |
| Principle: Floating 3 stages (I/U/UO) | |
| Absorption voltage: 28.8 Vdc | |
| Floating voltage: 27.2 Vdc | |
| Remote control (RCM-01/-02/-03) | ✔ |
Inverter
| Nominal battery voltage (Input range) | 48 Vdc (42 – 60 Vdc) |
| Power 30 min. 25°C | 400 VA |
| Continuous power 25°C | 300 VA |
| Power 5 min. 25°C | 600 VA |
| Power 5 sec. 25°C | 1000 VA |
| Asymmetric load | 200 VA |
| Max. efficiency (%) | 94% |
| Cos φ max. | 0.1 – 1 up to 300 VA |
| Detection of the load | 2 W only with the solar option -S |
| Short-circuit current AC 2 sec. | 4.6 Aac (9.2 Aac*) |
| Output voltage | Sine wave 230 Vac (120 Vac*) ±5 % |
| Frequency | 50 Hz (60 Hz*) ± 0.05 % (crystal controlled) |
| Consumption Stand-by / ON no load | 1.1 W**/ 5.2 W |
| Reverse polarity protection as internal fuse | 25 A |
General data
| Weight | 2.6 kg |
| Dimensions h/w/l [mm] | 142/163/84 mm |
| Conformity | low voltage directive (LVD) 2014/35/EU: EN/IEC 62109-1, 62109-2, 62477-1, electromagnetic compliance (EMC) directive 2014/30/EU: EN/IEC 61000-3-3, 61000-6-2, 61000-6-4, 62040-2 |
Ingress protection of enclosures IP30 | Operating temperature range -20 to 50°C | Relative humidity 95 % (non condensing) | Ventilation forced from 45°C ± 5°C | Length cables (battery/AC out) 1.2 m / 1 m | Acoustic level < 45 dB (with ventilation) | Approximate correction of Pnom -1.5% / °C from + 25°C | Recommended battery capacity > 5 x Pnom/Unom (recommended value in Ah)
Options
| Solar regulator | Voltage max. 90 Vdc |
| Current max. 10 Adc | |
| Principle: Floating 3 stages (I/U/UO) | |
| Absorption voltage: 57.6 Vdc | |
| Floating voltage: 54.4 Vdc | |
| Remote control (RCM-01/-02/-03) | ✔ |