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Charging solar batteries
How to choose the right generator for charging solar batteries and hybrid systems?
Only inverter and industrial generators with automatic start (2-Wire Start) and a pure sine wave are suitable for charging solar batteries and hybrid systems. The generator must start automatically via a signal from the inverter (hybrid inverter) and operate in the optimal load range of 30% to 70% of rated power.
14 items
SPARK 8000iA
1,255.00 € incl. 22% VAT
- Voltage
- 230 V
- Max. power
- 6.5 kW
- Rated power
- 6 kW
- Engine start
- Manual + electric (push-button)
- Sockets
- 1× USB-A 5V and 1x USB-C 5 V, 1× DC 12 V/9 A car socket, 1× Schuko 230 V/16 A, 1× 3P 230 V/32 A
SPARK 6000iA
1,570.00 € incl. 22% VAT
- Voltage
- 230 V
- Max. power
- 6 kW
- Rated power
- 5.5 kW
- Engine start
- Manual + electric (push-button)
- Sockets
- 2× 5 V USB-A, 1× DC 12 V/9 A car socket, 1× Schuko 230 V/16 A, 1× 3P 230 V/32 A
SPARK 8000 DiA
2,095.00 € incl. 22% VAT
- Voltage
- 230 V
- Max. power
- 6.5 kW
- Rated power
- 6 kW
- Engine start
- Electric (push-button), 2-wire automatic start
- Sockets
- 1× Schuko 230 V/16 A, 1× 3P 230 V/32 A
SPARK 13000iA
2,995.00 € incl. 22% VAT
- Voltage
- 230 / 400 V
- Max. power
- 10.5 kW
- Rated power
- 9.5 kW
- Engine start
- Manual + electric
SPARK 9000 DiA
3,150.00 € incl. 22% VAT
- Voltage
- 230 / 400 V
- Max. power
- 7.5 kW
- Rated power
- 7 kW
- Engine start
- Electric (push-button), 2-wire automatic start
- Sockets
- 1× Schuko 230 V/16 A, 1× 3P 230 V/32 A, 1× 5P 400 V/16 A
SPARK 10000 DiA
4,195.00 € incl. 22% VAT
- Voltage
- 230 / 400 V
- Max. power
- 9.5 kW
- Rated power
- 9 kW
- Engine start
- Electric (push-button), 2-wire automatic start
- Sockets
- 1× Schuko 230 V/16 A, 1× 3P 230 V/32 A, 1× 5P 400 V/16 A
SPARK 15000iA
5,395.00 € incl. 22% VAT
- Voltage
- 230 / 400 V
- Max. power
- 13 kW
- Rated power
- 12 kW
- Engine start
- Electric (push-button)
- Sockets
- 1× USB-A 5V and 1x USB-C 5 V, 1× 3P 230 V/16 A, 1× 3P 230 V/63 A, 1× 5P 400 V/32 A
SPARK 20000iA
5,665.00 € incl. 22% VAT
- Voltage
- 230 / 400 V
- Max. power
- 18 kW
- Rated power
- 17 kW
- Engine start
- Electric
SPARK BD 27 kVA
Price on request
- Voltage
- 400 V
- Max. power
- 22 kW
- Rated power
- 20 kW
- Engine start
- Electric
SPARK BD 50 kVA
Price on request
- Voltage
- 400 V
- Max. power
- 40 kW
- Rated power
- 36 kW
- Engine start
- Electric
SPARK BD 88 kVA
Price on request
- Voltage
- 400 V
- Max. power
- 70 kW
- Rated power
- 64 kW
- Engine start
- Electric
SPARK BD 110 kVA
Price on request
- Voltage
- 400 V
- Max. power
- 88 kW
- Rated power
- 80 kW
- Engine start
- Electric
Why do solar systems need an inverter generator with 2-Wire Start?
Connecting a conventional construction generator to modern hybrid inverters can cause faults or refusal to charge. To operate safely, the generator must meet two key conditions:
- Clean inverter voltage (Pure Sine Wave)
- SPARK inverter generators provide a stable frequency and a pure sine wave for safe charging of lithium (LiFePO4) or lead-acid batteries.
- 2-Wire Start (2-wire automatic start)
- When the battery state of charge (SOC) drops below a set threshold, the inverter sends a signal to the generator via two wires (dry contact); the generator starts automatically, charges the batteries and shuts down when the cycle is complete.
Overview of SPARK models for charging solar batteries
The golden rule for long generator life (30%–70% load)
When choosing generator power for solar systems, it is key to follow the optimal operating load rule:
The optimal operating load of a generator is between 30% and 70% of its rated power.
Why not below 30%?
If a generator runs below 30% load for long periods (so-called underloading), fuel combustion is incomplete, causing soot build-up on the valves and exhaust and shortening engine life.
Why not above 70%?
Continuous operation above 70%, or even close to 100%, causes overheating, higher oil consumption and accelerated wear of mechanical parts.
Example calculation
If your charger or inverter draws 3 kW from the battery bank, choose a generator with a rated power of at least 4.5 kW to 5 kW (e.g. SPARK 6000iA) so that it operates in the ideal load range.
SPARK petrol and diesel models with 2-Wire Start support
Petrol inverter generators with automatic start
The ideal choice for houses, weekend homes and smaller commercial buildings:
SPARK generator 6000iA: Compact and quiet petrol inverter model with built-in automation. Excellent for small to medium-sized hybrid solar systems.
SPARK generator 8000iA: A more powerful petrol unit for more demanding households.
SPARK generator 13000iA: Extremely powerful petrol inverter generator for larger buildings.
SPARK generator 15000iA with ATS: A premium solution with an integrated ATS switch and 2-Wire support.
SPARK generator 20000iA: Maximum capacity for private or commercial microgrids.
Diesel inverter generators with automatic start
Designed for users seeking maximum fuel economy and long service life:
SPARK generator 8000 DiA: Reliable diesel inverter generator with low consumption and 2-Wire Start support for off-grid buildings.
SPARK generator 9000 DiA: Upgraded diesel version for longer charging cycles.
SPARK generator 10000 DiA: Powerful diesel power source for larger battery banks on farms and in trade businesses.
Industrial systems with Baudouin engines for large battery arrays
For large industrial battery storage systems, farms and commercial buildings, we offer SPARK industrial diesel generators with Baudouin engines, which allow integration with BMS and 2-Wire automation:
SPARK 27 kVA with Baudouin engine: For smaller commercial buildings and farms.
SPARK 50 kVA with Baudouin engine: For medium-sized businesses and larger off-grid systems.
SPARK 88 kVA with Baudouin engine: For demanding industrial loads and fast charging of larger battery arrays.
SPARK 110 kVA with Baudouin engine: Top-tier power for production plants.
SPARK 165 kVA with Baudouin engine: For demanding infrastructure and commercial storage systems.
SPARK 275 kVA with Baudouin engine: Maximum backup power for the largest industrial systems.
Ensure uninterrupted operation of your solar system
Contact our technical experts for help choosing and configuring the right model for your solar inverter.
FAQ
Frequently asked questions
2-Wire Start (2-wire start) is a control interface that allows the generator to be connected to the solar inverter via two wires (dry contact). When the solar battery charge drops below a set threshold, the inverter automatically closes the contact, starts the generator and shuts it down when the batteries are sufficiently charged again.
Generators for solar systemsRunning below 30% of rated power causes incomplete fuel combustion, leading to soot build-up in the cylinders and exhaust system and clogged spark plugs/injectors. This significantly shortens the generator's life and increases maintenance costs.
Conventional generators with AVR protection often have excessive frequency and voltage fluctuations. Modern solar inverters are extremely sensitive and will reject such an input signal and not start charging the batteries; in the worst case, the inverter's electronics may be damaged.
Petrol inverter generators (e.g. SPARK 6000iA to 20000iA) are quieter, cheaper to buy and ideal for houses and occasional winter outages. Diesel inverter and industrial models (e.g. the SPARK DiA series and Baudouin generators), on the other hand, are better suited to off-grid buildings and industry, where the generator runs very often or continuously for many hours at a time.
Choose a generator where the charging power (in kW) is within 30% to 70% of the generator's rated power. For example: if your solar inverter charges the batteries at 4 kW, choose a generator rated between 6 kW and 8 kW (such as the SPARK 8000iA or SPARK 8000 DiA).
Use the power calculator