Service and warranty conditions

Replacement warranty for KOSTAL battery modules and BMS (Battery Management System)

Valid from: 01/01/2026

Dear Customer,

Your KOSTAL HELIVOR battery system is a quality product. KOSTAL Solar Electric GmbH guarantees the battery system's full functionality and freedom from material defects. These warranty conditions apply exclusively to the KOSTAL HELIVOR and not to connectable accessories such as inverters, sensors, Combiner Boxes, etc. Furthermore, the warranty is excluded should the unit be handled improperly.

Should any problems arise during or following the installation of your device despite diligent processing and monitoring, please contact your specialist company.

Should your specialist company not be able to start up the device without any problems or remedy faults during ongoing operation, our telephone-based customer support is on hand to assist them. The specialist company is your representative who can determine whether the device is defective and therefore needs to be replaced. Please note that only those persons with the necessary specialist knowledge and approval from the mains grid operator responsible for your device may carry out work on the mains grid.

10-year KOSTAL warranty

Your HELIVOR battery system is covered by a 10-year dealer warranty from the date on which it is first commissioned. The warranty period starts 12 months after delivery by KOSTAL at the latest. However, if the purchaser has written evidence of delivery to the site of installation, the warranty period start date can be defined as the date of delivery. The statutory warranty is not affected by this warranty.

Product warranty: KOSTAL guarantees that the product will remain free of material and manufacturing defects for a period of 10 years from the start of warranty subject to the exclusions and restrictions listed below.

Performance warranty: KOSTAL guarantees that the product

will retain 80% of its usable energy for a period of 10 years from the start of the warranty period
or will achieve the minimum throughput energy.

Depending on which occurs first if the product is installed and operated according to the installation and operating manual, manufacturer’s specifications and/or instructions.

The usable energy and the minimum throughput energy for each product model are listed in the table below:

Product model	Usable energy	Throughput energy
KOSTAL HELIVOR HV Module 3.2	3.2 kWh	10.2 MWh

Test conditions for usable energy: Fully charge and discharge the battery three times at 25 °C (± 3 °C) at a C-rate of 0.25. The highest value established from these three cycles is then taken as the value.

Exchange service

Replacing a product is very simple. Your specialist company contacts our customer support hotline and requests a replacement or creates a service request on our website under Service & Support > Contact.

In non-EU countries⁴ your specialist company must contact our local partner or, if there is no local contact, must contact the EU dealer. This person will call the customer service hotline and request a replacement and/or repairs to the device.

The following information is required for the claim to be accepted and processed:

Device type and serial number
Copy of purchase receipt
Commissioning date
Error message (where present) and other information concerning the fault
The log data of the inverter and battery (further information on reading the log data can be found in the operating manual of the inverter)
Detailed information concerning the complete system (devices, modules, string wiring, DC input data [currents, voltages] etc.)
In some cases, the service team will send you a registration form. Please complete and return to us.

You will normally receive an equivalent replacement device from us soon after. KOSTAL Solar Electric reserves the right to alter this process in special cases, meaning that your installer first has to send in the defective device. In non-EU countries¹, your device will be picked up by your local partner or the EU dealer for repairs, or this person will receive an equivalent replacement device from us. When the replacement device is shipped, the warranty period of your original battery system is automatically transferred to the replacement device. Your specialist company may only use this device for the exchange.

In terms of technical performance data, the replacement device rates at least on a par with your original battery system (e.g. SoH, year) unless a modification was required for technical reasons during further development. Replacement devices are not generally new devices, but repaired devices with a quality standard equal to that of series devices. Replacement devices may occasionally show minimal signs of wear.

Please note that the actual cause of failure can only be determined by the manufacturer directly. A recommendation of replacement by our customer support team does not therefore automatically imply that the issue is a warranty case. The final decision on whether warranty applies or not lies with KOSTAL Solar Electric GmbH.

Your specialist company will remove the defective device and install the replacement device. The replacement device will be commissioned. The defective device is then picked up from your specialist company or from you by our parcel service in the replacement device's original packaging or you will have to organise this with the help of the documents enclosed. KOSTAL Solar Electric reserves the right to alter this process in special cases, meaning that your installer first has to send in the defective device.

In non-EU countries⁴, the defective device must be sent to our local partner or dealer or, in the case of a repair, the defective device is removed by your specialist company and sent to the EU dealer.

The Service guide contains everything you need to know about the process.

Warranty exclusion

However, we have to reject warranty claims in the following situations:

Improper installation, maintenance or operation of the device
Software updates have not been carried out (see Software updates)
Software defects or non-compliant system settings are not covered by the warranty.
No maintenance or improper maintenance (e.g. lack of checks)
Improper use or incorrect installation site
Installation or operation in a country not approved by KOSTAL (see "Geographical validity")
Interventions, modifications or attempts to repair the device
Transport damage
Insufficient ventilation
Failure to observe valid and recognised good engineering practice, defining specifications relating to installation and safety (e.g. international DIN-IEC, European DIN-EN, in Germany DIN-VDE)
Damage caused by force majeure or external influences, e.g. storm damage, lightning strikes, overvoltage, fire, pollution, hail, flooding, line defects and animal bites
Incorrect layout or configuration of the photovoltaic system
The product has been subject to movement or shaking since being installed
The product has been exposed to temperatures exceeding 55 °C or below -10 °C charging temperature or -20 °C discharging temperature.
Malfunctions or damage that have been caused by the use of unapproved third-party products
Devices in which no defects can be detected in the factory during checking
If the purchaser is not able to provide KOSTAL or a KOSTAL partner with photos of the installation or other necessary product data if requested to do so after lodging a claim for warranty.
For signs of wear on the product (including, but not limited to scratches, flecks, mechanical wear, rust or mildew), which does not restrict its function or performance.
For damage to property or personal injury, incurred through a defect if the level of scientific or technical knowledge would not have enabled the defect to have been established at the time the product was sold to the purchaser.
For damage caused by inverters or chargers.
If the invoice for the product and the information listed under the Exchange service section was not presented along with the warranty claim.
If the serial number can no longer be identified on the product or has been changed.
If the purchaser has failed to report the issue to KOSTAL or a partner authorised by KOSTAL ("KOSTAL partner") within 10 days of the defect being established or the situation deteriorating.

Please note that damage of any kind, resulting from the reasons stated above, on the object covered by warranty or other equipment (e.g. on the solar system, automotive vehicles) is not covered by the warranty.

The warranty obligation does not apply to and no liability is accepted for transport damage as well as all other damage caused following the point when risk was transferred. The same applies to damage due to the use of incorrect packaging by the orderer.

Nor does the replacement warranty include any aesthetic defects that do not impact on the charging function.

Alongside safe operation, you yourself are responsible for correctly setting up, extending, modifying and maintaining the electrical system downstream of the house connection fuse. One thing you will need to do to ensure this is to make sure that the electrical system complies with recognised good engineering practice. We can only be held liable here when we are co-responsible for the damage as defined by statutory provisions. However, we can only be held liable in proportion to our contributory negligence.

Claims extending beyond the rights stated in the warranty conditions are not included in the replacement warranty if KOSTAL Solar Electric GmbH's liability is not prescribed by law. This is the case in particular for claims for compensation for damages arising directly or indirectly from device defects, for costs arising due to removal and installation or for claims for compensation for lost grid feed-in or lost self-consumption, etc. Any claims in accordance with the German Product Liability Act remain unaffected.

Software update

If the warranty beneficiary has not agreed to online access by KOSTAL Solar Electric GmbH, as an alternative the software updates can be installed independently by the warranty beneficiary. For this purpose KOSTAL Solar Electric GmbH only makes the software update available, free of charge. The additional costs incurred for updates undertaken by an installation company (travel costs, working time, etc.) are not borne by KOSTAL Solar Electric GmbH and must be borne by the warranty beneficiary.
Software updates are always published by KOSTAL Solar Electric GmbH at www.kostal-solar-electric.com > Download > Product > Update. The warranty beneficiary is responsible for regularly (at least every 3 months) viewing the publications and ensuring that the necessary software updates are installed. Software updates include not only adaptations of relevance to security and function, but also improvements to interfaces, known bug fixes and new functions on an ongoing basis. The timely installation of software updates therefore ensures the best possible performance and service support for the recorded product. Failure to update may invalidate the warranty. Use the auto-update function so you do not miss any updates. It is the responsibility of the warranty beneficiary to ensure that the Internet connection is maintained during the warranty period.

Replacement costs for EU countries (1-10 years)

You will receive the replacement device free of charge within the first 10 years if the defective battery system is sent to us within the specified period after receipt of the replacement device and the defect is covered by the warranty in accordance with the above conditions. In this case, the parcel service is also arranged by us at no cost to you. However, we do not cover transport costs and customs charges from or into EU overseas territories, as well as from and into countries outside of the EU if there is no KOSTAL Solar Electric sales company in the territory or country (see "Geographical validity"). Special regulations also apply for all islands (please enquire).

In addition to this, we will also reimburse your specialist company as goodwill with a fixed sum for replacing the battery system. You can view the current amount at any time on our website at www.kostal-solar-electric.com > Download > Product > Country > Service > Service Information and Prices. Please note that this fixed sum only covers the costs of the nearest specialist company. The warranty does not cover travel and accommodation costs resulting from engaging a specialist company that is not local to you. We are very happy to help you select a suitable specialist company.

KOSTAL Solar Electric GmbH may only be charged higher fixed sums by prior arrangement and in cases where special justification can be given. If this is not the case, we reserve the right to reduce the invoice amount accordingly.

Replacement costs for non-EU countries⁴ (10 years)

You will receive the replacement device at no charge if you have sent the defective battery system to our local partner within the specified period following receipt of the replacement device and if the defect is covered by warranty according to the conditions stated above.

In principle

However, we do not cover transport costs and customs charges from or into EU overseas territories as well as from and into countries outside of the EU if there is no KOSTAL Solar Electric sales company in the territory or country (see "Geographical validity"). Special regulations also apply for all islands (please enquire).

The warranty does not cover travel and accommodation costs or on-site installation costs resulting from engaging a specialist company that is not local to you.

In the event that a defect occurs during the warranty period for which we cannot be held responsible (exclusion of warranty), we shall invoice you for a flat-rate repair fee and shipping at a preferred price. You are however only entitled to this preferred price if the defective device is sent back to us and can be repaired. The original warranty of course continues to apply to the replacement device to the same extent.

Should we not receive the defective device, we will invoice you for the device price plus transport costs. In this case, you will only be entitled to the statutory warranty for the replacement inverter instead of our warranty.

All reimbursements can only be provided if the work to be done has been agreed in advance with KOSTAL Solar Electric GmbH and if it is submitted within 6 months of receiving the results of the analysis.

Geographical validity

These warranty conditions apply to all approved countries in accordance with the list of countries provided by KOSTAL Solar Electric GmbH. You can view the list of countries at any time on our website at www.kostal-solar-electric.com > Download > Product > Country > Operating manual > Released countries.

Transfer of ownership

KOSTAL Solar Electric GmbH retains ownership of the replacement device until the defective device is returned to us or, if the customer purchases a replacement device, until payment of the invoiced purchase price. In all cases, ownership of the defective device is transferred to KOSTAL Solar Electric GmbH when the replacement device is received.

Fixed sum for inspection

In the case of devices which are replaced within the warranty period as part of our exchange service, but upon inspection or analysis do not reveal any problems, we will apply a fixed inspection sum. You can view the price currently applicable on our website at www.kostal-solar-electric.com > Download > Product > Service > Service Information and Prices. Please note that the actual cause of failure can only be determined by the manufacturer directly. A recommendation of replacement by our hotline does not therefore automatically imply that the issue is covered by our warranty conditions.

Fixed sum for cleaning

Please return the defective device in clean condition. Devices contaminated by dust, paint, spores, mould, plant growth, ammonia gases, etc. can only be analysed and repaired once they have been cleaned. In such cases we will charge you a fixed cleaning sum.

Liability

For compensation for damages only, we limit our liability, including the liability of our employees or agents, to intentional damage or damage due to gross negligence. However, this limitation of liability does not apply to personal injury (bodily injury or death). It also does not apply when we would be held liable in accordance with contractually invariable, i.e. compulsory legal provisions, even in the event of absence of fault.

We hope that you are very pleased with your device!

KOSTAL Solar Electric GmbH

Frank Henn (Managing Director)

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