All‑In‑One Energy Storage System

This guide shows how to choose and size an All-In-One system: the inverter model, the battery cabinet, the PV array and a generator. It brings together the ratings in the All-In-One datasheets and manual and the Solinteg M2HT 25–50 kW documents. For installation and settings, use the All-In-One User Manual, the Solinteg M2HT 25–50 kW User Manual and the Solinteg M2HT 25–50 kW Paralleling & Generator Guide.

The All-In-One is manufactured by Solinteg and supplied and supported in Australia by AERL. The system design is the designer's responsibility: check it against the local standards, including AS/NZS 3000, AS/NZS 4777.1, AS/NZS 5033, AS/NZS 5139 and, for generators, AS/NZS 3010, and the network service provider's requirements for a grid connection.

1.1The All-In-One Range

1.2Steps

1. Choose the inverter rating for the load: continuous power, and the surge the back-up loads need (section 1.3).
2. Choose the battery cabinet for the energy and the battery power (chapter 02).
3. Design the PV array within the model's limits (chapter 03).
4. Size a generator, if the site needs one (chapter 04).
5. For more power, plan an off-grid parallel system (chapter 04).

1.3Inverter Rating

• Continuous load: the rated AC output must cover the largest continuous load on the back-up side.
• Surge: off-grid, the back-up side delivers 1.5 × its rated power for 10 seconds. Loads with a higher starting current (large motors, compressors) need a larger model, a soft starter, or a start sequence. If the overload protection operates, the inverter restarts; repeated overloads lengthen the restart time, up to 2 minutes.
• Unbalanced loads: each model supports 100% three-phase unbalance and half-wave loads.

2.1Battery Cabinets

Each AIO-25K to AIO-50K takes one Solinteg E2BR battery cabinet with 4 to 7 battery packs (LiFePO4, 314 Ah, 16.076 kWh per pack).

The All-In-One Max carries a Solinteg E2BR-S257K-C cabinet: 16 packs, 257.2 kWh (231.48 kWh usable at 90% DoD), 819.2 V rated (716.8–921.6 V), with a recommended charge and discharge current of 157 A.

2.2Energy

Divide the energy the battery must supply between charges (daily load from the battery × days of autonomy) by the usable energy, and choose the cabinet that covers it. For more storage than one cabinet holds, plan an off-grid parallel system: each inverter has its own cabinet.

2.3Battery Power

The battery's rated charge and discharge power is set by its 150 A current and its voltage, so it grows with the number of packs. When the load must run from the battery alone (at night, or off-grid without PV), the battery's rated power limits what the system delivers, whatever the inverter's rating:

Each cell is the lower of the inverter's rated output and the battery's rated power. For an AIO-40K or AIO-50K that must carry its full rating from the battery, choose the larger cabinets. The battery also charges at no more than its rated power, which limits how much PV it can absorb.

2.4Temperature

The battery packs charge between 1 and 50 °C and discharge between −20 and 50 °C. The cabinet's air conditioner (2 kW cooling and 2 kW heating) keeps the packs in range; allow for its consumption in the site's energy budget.

3.1Limits per Model

PV voltage

The inverter operates up to 950 V. Between 950 V and 1000 V it stops operating; above 1000 V it is damaged. Design every string so that its open-circuit voltage at the lowest expected cell temperature stays at or below 950 V.

3.2String Design

Use the PV module's datasheet values and its temperature coefficients:

1. Maximum modules per string: the string's open-circuit voltage at the site's lowest expected cell temperature must not exceed 950 V. V_max = N × V_oc × [1 + β_Voc × (T_min − 25 °C)], with β_Voc negative.
2. Minimum modules per string: the string's maximum power voltage at the hottest expected cell temperature must stay above the bottom of the MPPT range (200 V; 160 V on the AIO Max). For good yield, keep it near the rated 620 V.
3. Strings per MPPT: up to 2 (3 on the AIO Max). The strings' combined current must not exceed the MPPT's input current (40 A; 48 A), and their combined short-circuit current must not exceed 50 A (60 A). Each string input accepts up to 20 A on the AIO-25K to AIO-50K.
4. Same strings on one MPPT: modules of the same brand and model, at the same tilt and orientation, with the same string length.
5. Array power: the total must not exceed the model's maximum PV array power.

Each PV string connects to one inverter only. The M2HT 25–50 kW is not suitable for functionally earthed PV arrays (AS/NZS 5033): never earth the positive or negative pole of a PV string.

3.3Example: AIO-50K

An example module (use your module's own datasheet): 550 W, V_oc 49.6 V, V_mp 41.6 V, I_sc 14.0 A, I_mp 13.2 A, β_Voc −0.25%/°C, β_Pmax −0.35%/°C. Site minimum cell temperature −5 °C; hottest cell temperature 70 °C.

The Vmp line uses the power coefficient as an estimate of the voltage coefficient; use the module's Vmp coefficient where its datasheet gives one.

4.1Generator Sizing

The generator and the inverters never supply the loads at the same time

Size the generator and the inverter system so that each one on its own can supply the full load.

• Generator rating: at least the full site load, including starting currents. On the AIO-25K to AIO-50K the generator connects to the GEN port, which accepts up to the model's generator input rating (30.0 / 36.0 / 36.0 / 48.0 / 60.0 kVA; 45.5 / 54.5 / 54.5 / 72.7 / 90.9 A).
• Other connections: a single system can also take the generator through an automatic transfer switch (ATS) with the grid, or on its on-grid port where there is no grid; an off-grid parallel system takes it on the master's on-grid port. The M2HT 25–50 kW Paralleling & Generator Guide shows each solution; confirm the firmware with AERL.
• Charging from the generator: in the "loads and battery" output mode the generator supplies the loads first and charges the battery with the rest: charge power = generator maximum output − load power. To charge the battery at its rated power while the loads run, the generator must cover both.

• Control: a three-phase generator that starts and stops on a dry-contact signal from the inverter. Control is manual, automatic (starts when the grid fails), or by SOC (starts below the start SOC and stops at the stop SOC). To set up automatic or SOC start, contact AERL.
• All-In-One Max: it has no GEN port. Contact AERL to design its generator connection. Never connect a generator directly to the back-up side.

Generators must meet AS/NZS 3010.

4.2Off-Grid Paralleling

Up to 10 All-In-One systems of the same model and rating can run in parallel on the back-up side, with no grid connection, for 50–500 kW (off-grid parallel). The total power is the number of systems × the rating of one. One master controls the system and shares the power on each phase evenly across the inverters.

• Each inverter has its own battery cabinet and its own PV strings.
• If a slave fails, the master isolates it and the system keeps running; if the master fails, the whole system shuts down.

For an All-In-One Max parallel system, contact AERL for the maximum number of systems. The All-In-One Max is for off-grid use: its grid connection is pending CEC listing.

4.3Worked Example: Off-Grid Workshop

An off-grid workshop has a 35 kW continuous load with a 45 kVA motor start, uses 70 kWh overnight from the battery, and has a diesel generator for long cloudy periods.

5.1Warranty

The All-In-One cabinet and battery carry a 10-year product warranty and a 10-year, 70% performance warranty; the M2HT inverter carries 5 years, with an optional extension to 10 years. The warranty starts on the earlier of commissioning and six months after delivery to AERL. Conditions apply: see the All-In-One Warranty Statement, at aerl.com.au.

5.2Design Support

Contact AERL support on 1800 950 865 or [email protected] for help with a design: parallel and generator systems, firmware, and grid connection.

5.3Change Log