Technical Support for Your Solar System & Final Registration

How Inverters Behave During a Power Outage | Emergency Power, Backup Power & Off-Grid Capability Explained

Effects of Shading | Understand and Minimise the Impact | Bypass Diodes | Solutions for Your Roof

Types of Inverters & Their Differences | Key Criteria and Questions Before Buying

How Does an Electric Car Charge? | Charging Options with an EV Charger

Strings vs MPPTs | Understanding Solar Panel Wiring

Choosing Battery Storage | Size & Manufacturer | A Practical Selection Guide

Huawei | Off-Grid Operation Now Possible with Backup Box | IP65 Battery Storage & 15-Year Warranty

Methods for Planning Your Roof Layout Efficiently and Easily

Solis Cloud | Migration

Intersolar 2025 | SolarEdge: Fully optimised – flexible, safe and intelligent

Intersolar 2025 | SolaX: Hybrid inverters, Triple Power batteries and smart accessories

Intersolar 2025 | Consolinno HEMS – Intelligent energy management and optimised control

Intersolar 2025 | Huawei – Excellent features, but can they be disabled? Heating, backup power and smart control

Intersolar 2025 | BYD unveiled: More power, less space – three battery highlights

Intersolar 2025 | 100 years of KACO | Advanced energy management with Consolinno HEMS

SMA hybrid inverters | Sunny Boy Smart Energy | Smart Home battery with BMS | Intersolar 2024

Fronius Symo GEN24 12 kW | Verto Plus | Backup solution | Backup Controller up to 35 A

Victron Energy | MultiPlus | Quattro | MPPT | Off-grid and grid-parallel systems | Intersolar 2024

Qcells Q.TRON solar panels | TOPCon cells | ESS HYB-G3 data logger | Dual BMS | EV charger

Trina Solar | Vertex S + Series | Full & Clear Black | Double Glass Modules | TopCon | intersolar 2024

Solis | Intersolar 2024 | Hybrid inverters | MPPT trackers | Solar trade fair | Low voltage

SofarSolar | Hybrid inverters up to 20 kW | HYD-5 | EV AC charger | Cloud control | Dynamic electricity tariffs

my-PV | Solar-powered hot water | SOL-THOR world first | AC THOR 9S | AC ELWA 2 | Variable heating element

Kostal | Plenticore G3 | Made in Germany | Universal WR | 3 devices in 1 | small mounting distance

Solis | new 3ph WR | LV & HV | very open system | SolisCloud | great price/performance ratio

BYD | Market leader in battery storage? | HVM and HVS | One million batteries sold

Tigo optimisers | How they work and when they make sense | Optimising shaded panels

E3/DC | Bidirectional charging with VW | World first | 360° self-sufficiency | Off-grid capability | Intersolar 2024

JA Solar | 455 W solar panels | Monofacial and bifacial | 22.8% efficiency | IP68 certified

Fox ESS | H3 AC3 series | 5 - 30 kW | German service | grid-connected inverters

K2 Systems | New façade systems | Roof design with K2 Base | Visualising snow loads on panels

Pylontech | Pelio replaces US5000 low-voltage battery | New Force H3 high-voltage battery generation

Why does a solar battery make sense?

A solar battery is an important part of a modern solar power system because it can significantly increase the share of solar electricity used on site and improve the system’s economics. Instead of exporting all surplus solar power to the grid, stored energy can be used directly in the household. Depending on the system and consumption profile, this can raise self-consumption considerably—potentially to as much as 85%.

Higher self-consumption and lower costs

Rather than exporting surplus solar electricity and later buying more expensive electricity from the grid, a solar battery makes stored solar power available for household use. This reduces grid consumption, can lower electricity costs and increases independence from future electricity-price rises. A high self-consumption rate can make the entire solar system more efficient and economical.

Flexible battery options

A wide range of lithium-ion battery systems is available for new and existing solar installations and for different inverter platforms. The battery should be designed professionally and selected to match the individual system, consumption profile, inverter and backup requirements.

Is a solar battery worth buying?

A solar battery can be worthwhile in many cases, particularly if you want to maximise self-consumption of your solar electricity and reduce exposure to rising electricity prices. A battery allows you to use your own solar power when the sun is not shining, for example in the evening or on cloudy days. This can improve both independence and the system’s economics.

Example of savings and payback period
Assume an electricity price of €0.30 per kWh and an increase in self-consumption from 30% to 70% through battery storage. For a 5 kWp solar system producing around 5,000 kWh per year, the savings could be approximately €600 per year. With battery investment costs of €3,000 to €6,000, this example gives a payback period of around five to ten years, depending on the individual circumstances.

A solar battery can also reduce grid-electricity consumption and increase the share of self-generated renewable electricity used in the household.

How do I choose the right battery size for my solar system?

The optimal solar battery size should be at least equal to the rated power of the inverter, using a minimum ratio of 1:1. For example, an 8 kW hybrid inverter should be paired with a solar battery of at least 8 kWh. A battery with twice the capacity of the inverter’s rated power—a 2:1 ratio—can be preferable. A battery that is too small cannot absorb all available solar energy and may be subjected to greater stress.

Why should a solar battery have twice the capacity in kWh as the inverter’s rated power in kW?

First: Technical reasons
If the inverter has a higher rated power than the solar battery, the battery may not be able to absorb all the available energy. Consider a battery that is only 10% charged: if a large inverter then operates at full power, harmonic oscillations can occur and place additional stress on the battery.

Second: Practical use
The solar battery should not only be useful on sunny summer days, but also across longer periods such as a rainy week or during spring and autumn. A larger battery can help cover more electricity consumption with solar energy.

Conclusion
A 2:1 ratio—a solar battery with twice the capacity in kWh as the inverter’s rated power in kW—has proved effective in practice. A 1:1 ratio is often selected for cost reasons and can also be suitable. As a general design principle, the battery should not be undersized relative to the inverter if efficiency and battery service life are to be maximised.

What is the difference between low-voltage and high-voltage battery systems?

Difference between low-voltage and high-voltage solar batteries

When choosing a solar battery, it is important to distinguish between low-voltage and high-voltage systems. Each type has specific advantages and applications, which often depend on the size of the solar installation and the selected inverter.

Low-voltage solar batteries

In residential applications, low-voltage batteries commonly operate at 48 volts and are widely used. Their lower operating voltage can simplify certain system designs. Larger low-voltage systems may require larger cable cross-sections or multiple parallel cables; this is straightforward with systems such as Pylontech US batteries. Many low-voltage products incorporate their own battery management functions, which can reduce the number of external components required. Larger systems can also be built by using the appropriate parallel cabling and manufacturer-approved configuration.

High-voltage solar batteries

High-voltage batteries generally operate above 120 volts and are often used with larger solar systems. The higher voltage enables energy transfer at a lower current, reducing cable losses and allowing smaller cable cross-sections. The battery modules are usually connected in series and require a compatible battery management system. Depending on the product, this additional BMS can increase the system price. High-voltage systems often provide simpler cabling across different storage capacities.

Conclusion

The choice between a low-voltage and high-voltage battery depends on the solar-system size, inverter architecture, required battery power and compatible products. Low-voltage batteries can be a cost-effective solution for small and medium-sized systems and can also be scaled with suitable cabling. High-voltage batteries are frequently advantageous in larger installations because they operate at lower currents and can simplify the cabling.

Can I expand my PV storage system?

Yes, most PV storage systems are modular in design and can be easily expanded. Depending on the manufacturer, storage groups of around 12 to 30 kilowatt hours capacity can be put together.

In addition, these storage groups can often be extended by further identical groups, thus doubling their capacity. This offers a high degree of flexibility if the energy demand of the household increases or a larger amount of solar power is to be stored. For such extensions, a distributor, also HUB is usually required, required to efficiently connect the various storage groups with each other.

It is important to check the compatibility of the individual battery packs , as not all systems can be combined with each other at will. When planning a storage expansion, attention should also be paid to the inverter capacity to ensure that the overall system functions optimally. We will be happy to advise you on selecting the right configuration and ensure that the battery management systems (BMS) of the individual storage components are compatible with each other.

Can retrofitting a solar battery cause problems?

Yes. When adding modules to an existing solar battery, newly manufactured battery modules often arrive with a state of charge of around 40% to 60%. They should not simply be connected to existing modules that may be fully charged or discharged. Different states of charge can create imbalances within the system, reduce performance and cause faults.

The new battery modules should therefore be brought to the same state of charge as the existing modules before they are connected. Follow the battery manufacturer’s instructions and compatibility requirements to ensure safe integration.

How safe are LiFePO4 solar batteries?

LiFePO4 (lithium iron phosphate) solar batteries are considered very safe compared with other lithium-based battery technologies. Their most important safety characteristics include:

• Thermal stability: LiFePO4 batteries have high thermal stability and are less susceptible to overheating or thermal runaway, significantly reducing the risk of fire or explosion.
• Fire safety: Their chemistry is comparatively resistant to ignition when batteries are overcharged or damaged.
• Long service life: A typical service life of up to 10–15 years reduces degradation-related risks, provided the battery is operated within the manufacturer’s specifications.
• Robust construction: LiFePO4 cells are mechanically stable and resistant to damage, reducing the risk of internal short circuits.
• Low risk of explosion: Their chemical composition offers a comparatively low risk of explosions or uncontrolled energy release.

Overall, LiFePO4 batteries are a safe choice for solar applications, particularly in homes and other environments where safety is a high priority. Correct installation, compatible components and compliance with the manufacturer’s instructions remain essential.

When will my delivery arrive?

The estimated delivery time is always shown on the product page in the online shop and is updated automatically several times a day.
Once your goods have been dispatched, you will receive the delivery note and tracking information by email.

I want to collect my order. How do I arrange an appointment?

You can collect ordered and fully paid goods from the warehouse in Paderborn. Payment on collection is not possible.
Your invoice includes a link to the collection calendar, where you can select your preferred collection appointment.
Collection without prior notice and an agreed appointment is not possible.

Address:
MMR Logistic
Senefelderstrasse 7-7a
33100 Paderborn, Germany

How much does shipping cost?

You can find information about shipping costs here.
For parcel and freight deliveries to certain countries and non-EU destinations, add the desired products to your cart and complete the address form. The shipping-cost calculator will then display the applicable freight costs.

My goods arrived damaged or incomplete – what should I do?

Check your delivery immediately upon arrival for completeness and for visible or concealed transport damage.

The following applies to private customers:

If a parcel or pallet is damaged, or if a component listed on the delivery note is missing, inform the courier or freight carrier immediately so that the issue can be recorded.

Also send a written damage report without delay, including a brief description and clear photographs. The fastest option is the chat icon at the bottom right of the website, where images can be attached directly and the report assigned to a contact person.

If you confirm that the goods were received complete and undamaged despite obvious damage or missing items, and do not report the issue within one day, you may lose your right to reimbursement.

Concealed damage should be reported in writing immediately and no later than seven calendar days after receipt of the goods to preserve a possible reimbursement claim.

Why are my previous orders no longer visible?

My customer account is no longer visible

The new solar online shop has been live since February 2023.

Unfortunately, customer accounts could not be transferred from the previous online shop. Your order will still be processed as normal, and you have not lost your position in the processing queue.

Previous orders cannot be displayed in the new online shop. The former shop did not provide online delivery-status information either, so no important status information has been lost.

Please accept our apologies for the inconvenience.

P.S. If the FAQs and other information do not answer your question, use the communication tool at the bottom right of any shop page.

Why are my previous orders no longer visible?

My customer account is no longer visible

The new solar online shop has been live since February 2023.

Unfortunately, customer accounts could not be transferred from the previous online shop. Your order will still be processed as normal, and you have not lost your position in the processing queue.

Previous orders cannot be displayed in the new online shop. The former shop did not provide online delivery-status information either, so no important status information has been lost.

Please accept our apologies for the inconvenience.

P.S. If the FAQs and other information do not answer your question, use the communication tool at the bottom right of any shop page.

How can I change my order?

If you want to change your order, please proceed as follows:

• Place the entire revised order again in the online shop.

• Add the following note in the order-notes field: Change to previous order VGXXXX.

• The original order will then be cancelled and the new order processed instead.

You will not lose your position in the processing queue because of the new order number. The revised order will be assigned the same internal position.

Written confirmation that the original order has been cancelled can take up to 14 days.

Thank you for your patience.

How do I cancel my order?

To cancel your order, contact us during business hours (Monday to Thursday, 9:00 a.m.–5:00 p.m.; Friday until 2:00 p.m.) using the communication tool on the website. Click the black contact icon at the bottom right of the page.

Your cancellation must be submitted in writing and specify which item or items should be cancelled.

It can take up to 14 days to receive written confirmation of your cancellation. Your cancellation is nevertheless legally received as soon as it reaches us.