Heiwit warranty conditions for Switzerland

Preamble

Heiwit S.p.A., with registered office at Via Carlo Robbioni 2, 21100 Varese (Italy), VAT number 03980400125 (“Heiwit”), markets under its own brand electricity storage systems based on sodium-ion batteries, inverters and accessories. In Switzerland, Heiwit products are imported and sold by JAN Suisse SA (the “Importer”) through the online shop SodiumStorage.ch.

These conditions govern the voluntary warranty that Heiwit, as manufacturer, grants in Switzerland to the Buyer for the products listed in Article 2. They are the Swiss edition of the Heiwit warranty conditions (Edition 3 of 22 October 2026), adapted to the SodiumStorage.ch sales channel and to Swiss law.

The conditions consist of a general part, applicable to all products, and three annexes setting out the rules specific to each product: Annex B for the battery, Annex I for the inverters and Annex A for the accessories. In the event of conflict, the annex prevails for the product concerned.

The warranty is free of charge and is in addition to the rights that the law grants the Buyer against the seller, without replacing or limiting them (Article 3).

General part

Article 1 — Definitions

1.1 Product: each Heiwit-branded product listed in Annexes B, I and A, identified by its serial number or, if it has none, by the product code and the purchase document.

1.2 Battery, Inverter, Accessory: the Products described in Annexes B, I and A respectively.

1.3 Buyer: the natural or legal person who purchases the Product new for end use in Switzerland:

• directly from the Importer, by placing an order on SodiumStorage.ch or through the shop’s channels (contact form, email, WhatsApp); or
• from a Qualified Installer who purchased the Product from the Importer through SodiumStorage.ch.

A Consumer is a Buyer who is a natural person and purchases the Product for personal or family use unrelated to their professional or commercial activity.

1.4 Qualified Installer: the electrical installation company that holds the installation permit required for the work carried out under the Low-Voltage Installation Ordinance (NIV, SR 734.27) and that installed the Product.

1.5 Importer: JAN Suisse SA, which imports Heiwit Products into Switzerland and sells them through SodiumStorage.ch. It is the Buyer’s contact in Switzerland for registration and warranty claims; its details are given at the top of this page.

1.6 System: all the Products connected to the same Inverter and registered under the same identifier in the Heiwit monitoring system.

1.7 Activation Date: the date on which the Product was commissioned, as shown by the registration under Article 6.

1.8 Sale Date: the date of the invoice by which the Importer sold the Product to the Buyer or to the Qualified Installer.

1.9 Datasheet and manual: the documents for the model published by Heiwit and in force on the date of purchase of the Product.

1.10 Reference Price: the lower of the price of the Product shown separately on the Buyer’s purchase invoice and the selling price of the Product on SodiumStorage.ch on the Sale Date, in both cases in Swiss francs, excluding VAT, shipping costs and installation costs. If the invoice does not show the price of the Product separately, the SodiumStorage.ch price applies.

1.11 Warranty Period: the duration stated in the Annex for the Product, starting as set out in Article 6.

1.12 The definitions specific to the Battery (Nominal Capacity, Residual Capacity, Reference Measurement, Energy Delivered) are set out in Article B1.

Article 2 — Products covered and products of other brands

2.1 The warranty covers Products sold new by the Importer through SodiumStorage.ch, directly to the Buyer or to a Qualified Installer, and installed in Switzerland: the NA-48V210Ah sodium-ion battery (Annex B), the Virgo and Lybra inverters (Annex I) and Heiwit-branded accessories (Annex A).

2.2 Heiwit Products purchased through other channels remain covered by the Heiwit warranty conditions applicable to those channels, published on heiwit.com.

2.3 The 7.78 kWh NA-48V170Ah battery, on sale from early 2027, does not fall within this edition: its warranty conditions are communicated with the order confirmation and published on this page before the first deliveries.

2.4 The warranty is granted for the use of the Products for self-consumption, at domestic or non-domestic premises, in the configurations permitted by the manual. Excluded uses are set out in Article 13.

2.5 Products of other brands sold together with the Products, including within a kit — for example routers — are covered by the warranty of their respective manufacturer, on its terms. Heiwit does not extend that warranty or assume it as its own; Heiwit and the Importer assist the Buyer in making the claim to the manufacturer. In a kit, each component is subject to its own warranty.

2.6 Switchboards, wiring, mounting structures, the electrical installation and other components not supplied by Heiwit are not covered.

Article 3 — Statutory rights of the Buyer

3.1 By law, and free of charge, the Buyer retains the warranty rights for defects in the item sold against the Buyer’s own seller — the Importer or the Qualified Installer from whom the Buyer purchased — under Articles 197 et seq. of the Swiss Code of Obligations (CO). For Consumers, the limitation period for new products may not be less than two years from delivery (Art. 210 CO). This voluntary warranty is in addition to those rights and does not affect them.

3.2 No clause of these conditions may be interpreted as excluding, reducing or making subject to conditions the rights that the law grants the Buyer, or the manufacturer’s liability under the Federal Product Liability Act (PrHG).

Article 4 — Warranty against defects

4.1 Heiwit warrants that the Product is free from defects in materials and workmanship for the period stated in the relevant Annex: ten years for the Battery and the Inverter, two years for Accessories, starting as set out in Article 6.

4.2 The warranty covers the components of the Product supplied by Heiwit, including the management software installed on the Product.

4.3 Normal wear and tear and, for the Battery, the reduction in capacity due to use and the passage of time are not defects within the meaning of this Article. The capacity of the Battery is governed exclusively by the performance warranty in Article B3.

Article 5 — Laboratory data and performance in operation

5.1 The values in the Datasheet and in the information material of Heiwit and SodiumStorage.ch — including capacity, number of cycles, depth of discharge, efficiency, power and switchover time in the event of a grid outage — are obtained in laboratory tests, under the conditions stated alongside each value. They describe the Product and allow it to be compared with others; they are not covered by this warranty, which comprises only the warranty against defects in Article 4 and, for the Battery, the performance warranty in Article B3.

5.2 The energy and power available in daily use may be lower than the nominal values and vary over time, in particular depending on temperature, solar irradiance, the power demanded, the Inverter and grid settings, the calibration of the Battery management system and the system’s own consumption. These variations do not constitute a defect nor, for the Battery, a reduction in Residual Capacity, which is determined solely by the Reference Measurement.

5.3 Heiwit does not warrant any economic or energy results of the System, such as the output of the photovoltaic modules, savings on electricity bills, the self-consumption rate, the payback period of the investment, the remuneration for energy fed into the grid or access to subsidies.

5.4 Statements by the Importer, Qualified Installers or any party other than Heiwit, including the replies of the SodiumStorage.ch automated assistant, do not modify or extend this warranty.

Article 6 — Registration and start of the warranty

6.1 The Products are registered by the Qualified Installer at the time of commissioning, in the Heiwit monitoring system or by sending the data to the Importer, which forwards it to Heiwit. Registration includes: serial numbers, Activation Date, address of the System, details of the Qualified Installer and of its installation permit, and details of the Buyer.

6.2 The Buyer bears no registration obligation; failure by the Qualified Installer to register, or late registration, does not affect the Buyer’s rights. In that case the Buyer may send the data to the Importer.

6.3 The Warranty Period starts on the Activation Date and in any event no later than six months after the Sale Date. If no Activation Date has been registered, it starts on the date of the Buyer’s purchase invoice, again subject to the same limit; if that date is not available either, it starts from the sixth month following the Sale Date.

6.4 For Accessories purchased separately, including as spare parts, the Warranty Period starts on the date of the purchase invoice or, failing that, on the Sale Date.

6.5 Heiwit, directly or through the Importer, informs the Buyer of the start date with the confirmation of registration, where it knows the Buyer’s contact details, and in any event at the Buyer’s request.

Article 7 — Conditions of use

7.1 The Product must be stored, installed and used in accordance with the manual, the Datasheet and the conditions of use stated in the Annex for the Product. The warranty does not cover defects and damage caused by failure to comply with these instructions; an irregularity that did not cause the defect does not invalidate the warranty.

7.2 The Product must be installed by a Qualified Installer, in accordance with the manual and Swiss technical rules, in particular the Low-Voltage Installation Standard (NIN), the grid operator’s requirements and fire-protection regulations; removal and reinstallation must be carried out in the same way. The warranty does not cover defects and damage caused by installation, removal or reinstallation carried out by anyone not holding the required installation permit.

7.3 If the Datasheet in force on the date of purchase states wider limits for the conditions of use listed in the Annexes than those given there, the limits in the Datasheet apply.

Article 8 — Monitoring, updates and operating parameters

8.1 The Buyer must keep the System connected to the Heiwit monitoring system via the Buyer’s own internet connection: the connection is used for remote diagnosis and updates. For the Battery, prolonged disconnection has the consequences set out in Article B5.6. Data is processed in accordance with Article 16.

8.2 The Buyer agrees to the installation of management software updates released by Heiwit, including remotely via the monitoring system.

8.3 For safety reasons or to protect the service life of the Products, Heiwit may modify the operating parameters remotely, such as power, temperature and state-of-charge limits. If a modification appreciably reduces the energy or power available in operation, Heiwit informs the Buyer before applying it, stating the reason. Settings required by the Swiss grid operator are not modified without the agreement of the Qualified Installer.

8.4 The warranty does not cover damage directly attributable to the Buyer’s refusal of a corrective update notified in writing by Heiwit together with a statement of the consequences.

Article 9 — Claims for warranty service

9.1 The claim is submitted to the Importer, which forwards it to Heiwit and follows the case: using the SodiumStorage.ch contact form, by email or on WhatsApp. It may also be submitted through the Qualified Installer or directly to Heiwit, by writing to [email protected] or calling +39 0332 1730555. Claims are accepted in Italian, French, German and English.

9.2 The claim must be submitted within the Warranty Period and, on pain of forfeiture of the rights under this voluntary warranty, within two months of discovering the defect. Article 3 remains unaffected.

9.3 The claim must include: serial numbers or codes of the Products concerned, Activation Date, a description of the defect or complaint, and photographs of the installation and of the identification plate. Operating logs are retrieved by Heiwit from the monitoring system; the Qualified Installer attaches them when the System is not monitored. Heiwit or the Importer may request a copy of the purchase invoice and of the safety certificate (SiNa) for the installation required by the NIV.

9.4 In the event of anomalies that may pose safety risks — including overheating, odours, smoke, deformation of the enclosure or system alarms — the Buyer must stop using the Product, have it taken out of service by a Qualified Installer and must not open or tamper with it.

9.5 Heiwit assigns the claim a case number, which it communicates to the Buyer, the Importer and, if involved, the Qualified Installer. If necessary documents are missing, Heiwit requests them within five working days. It carries out an initial check on the monitoring data and communicates the outcome within fifteen working days of receiving the complete claim. If a deadline cannot be met, Heiwit informs the Buyer, stating the reason and the new date. If the remote check is not conclusive, Heiwit arranges for an on-site visit by a Qualified Installer or an appointed technician and, where the complaint concerns the capacity of the Battery, for the Reference Measurement. The Buyer must allow access to the Product on the days and at the times agreed.

9.6 The Product found to be defective is repaired or replaced within thirty working days of the defect being established, except for causes not attributable to Heiwit.

Article 10 — Remedies

10.1 Once it has been established that the warranty applies, Heiwit, at its option, repairs the Product or replaces it with a new or refurbished Product. The replacement Product is of the same model or, if this is no longer available, of a model compatible with the System and with equivalent or better characteristics.

10.2 Where repair and replacement are not possible, in particular because no product compatible with the System is available, or where the Buyer agrees, Heiwit pays the residual value of the Product instead. In relation to a Buyer who is not a Consumer, Heiwit may in any case opt for the residual value.

10.3 The residual value is equal to the Reference Price reduced, for each month elapsed since the start of the warranty, by a fraction equal to one divided by the number of months in the Warranty Period of the Product (one hundred and twentieth for the Battery and the Inverter, one twenty-fourth for Accessories). It is paid in Swiss francs.

10.4 Payment of the residual value extinguishes the warranty on the Product to which it relates. The total amounts paid for the same Product may not exceed the Reference Price.

10.5 The replaced Product becomes the property of Heiwit.

10.6 The remedies in this Article, together with the rules specific to the Battery in Article B8, are the only remedies provided by this voluntary warranty; the statutory rights under Article 3 remain unaffected.

Article 11 — Repaired or replacement Product

11.1 The repaired or replacement Product is covered by the warranty for the remaining period of the original Product and in any case for no less than 360 days for the Battery and the Inverter and ninety days for Accessories, from the date of repair or replacement.

11.2 Repair or replacement does not renew the Warranty Period; for the Battery, it does not reset the count of Energy Delivered, which continues on the replacement Product.

11.3 Where necessary for the correct operation of the System, Heiwit may also replace other Products in the same System; this Article applies to them.

Article 12 — Costs of warranty service

12.1 For service accepted under the warranty and authorised by Heiwit, Heiwit bears the labour and travel costs of the Qualified Installer or appointed technician and the costs of transporting the defective Product and the replacement Product between the System and Heiwit, including customs formalities and import taxes. The Buyer bears no costs.

12.2 Heiwit does not reimburse costs incurred without its written authorisation, nor extraordinary costs of access to the Product, such as building work, scaffolding or lifting equipment, arising from a location not in accordance with the manual.

12.3 The defective Product is returned in the packaging supplied by Heiwit; the Battery is transported in compliance with the regulations on the carriage of dangerous goods (ADR).

12.4 If the check establishes that the claim is not covered by the warranty because of one of the grounds for exclusion, or that the Product does not correspond to the one stated in the claim, Heiwit may charge the Buyer the travel, transport and inspection costs, provided that it informed the Buyer of the amount before the service was carried out.

Article 13 — Exclusions

13.1 The warranty does not cover defects and damage resulting from:

• installation, configuration, maintenance, removal or reinstallation not in accordance with the manual or the technical rules;
• work, repairs, opening or modifications, including to the software, carried out by personnel not authorised by Heiwit;
• use or storage of the Product outside the conditions of Article 7 and of the Annex for the Product;
• connection to products that the manual does not list as compatible;
• use of the Products in the course of a professional activity of buying and selling energy or providing grid services to third parties, unless the service is offered or authorised in writing by Heiwit; the operating modes provided by the Inverter, including charging the Battery from the grid, remain covered when used for self-consumption;
• transport or handling after delivery to the Buyer;
• lightning, overvoltage, fires of external origin, flooding, water infiltration, earthquakes and other natural events or force majeure;
• vandalism, theft, wilful damage, animals;
• failures of components of the electrical or photovoltaic installation not supplied by Heiwit;
• normal wear and tear and purely cosmetic damage that does not affect operation;
• removal, alteration or illegibility of the serial number;
• normal reduction in the capacity of the Battery within the limits of Article B3.

13.2 The exclusions specific to each Product are set out in the relevant Annex.

13.3 If the defect is caused by non-compliant installation, configuration or storage attributable to the Qualified Installer, Heiwit provides the Buyer and the Importer with a technical report stating the cause established and, on request, a quotation for restoring the Product. The Buyer’s rights against the Qualified Installer remain reserved.

13.4 When it rejects a claim in whole or in part, Heiwit states in writing the reason and the technical evidence on which it is based. The Buyer may challenge them within sixty days by providing evidence to the contrary; in that case the check is repeated jointly, in the presence of the Buyer or a technician of the Buyer’s choice.

Article 14 — Limitation of liability

14.1 To the extent permitted by law, and except in cases of intent or gross negligence, personal injury and liability under the Federal Product Liability Act, Heiwit’s liability arising from these conditions is limited to the Reference Price of the Product and does not extend to indirect damage, including loss of energy production or self-consumption, loss of savings on electricity bills, loss of subsidies and commercial losses.

Article 15 — Transferability

15.1 The warranty follows the Product. If the property in which the Product is installed is transferred, the warranty passes to the new owner, subject to notification to Heiwit or the Importer within sixty days of the transfer.

15.2 The transfer does not renew the Warranty Period or reset the count of the Battery’s Energy Delivered. A Product removed from the original System and reinstalled elsewhere in Switzerland remains covered if the reinstallation is carried out by a Qualified Installer and registered in accordance with Article 6.

Article 16 — Processing of personal data

16.1 The data collected for the registration of the Products and the operating data acquired by the monitoring system are processed by Heiwit in Italy for the performance of the warranty and kept for the entire Warranty Period, in accordance with the privacy notice available on heiwit.com. Italy has a level of data protection recognised as adequate by Switzerland.

16.2 The Importer processes the registration and claim data in order to manage the warranty, in accordance with its privacy policy.

Article 17 — Final provisions

17.1 This Edition CH 1 enters into force on 24 October 2026 and applies to Products sold by the Importer from that date; as it is more favourable to the Buyer, it also applies to Products sold previously through SodiumStorage.ch. Subsequent editions do not apply to Products already purchased unless they are more favourable to the Buyer.

17.2 The Importer makes these conditions available to the Buyer with the order confirmation and on this page. A Qualified Installer who resells the Product must provide the Buyer with a copy, on paper or on another durable medium, no later than on delivery.

17.3 These conditions are drawn up in Italian and translated into French, German and English; in the event of discrepancies, the Italian text prevails.

17.4 The invalidity of any clause does not affect the validity of the others.

Article 18 — Applicable law and jurisdiction

18.1 These conditions are governed by Swiss law, to the exclusion of the United Nations Convention on Contracts for the International Sale of Goods (Vienna Sales Convention, CISG).

18.2 For disputes with Buyers acting as Consumers, the courts at the Consumer’s domicile have jurisdiction; other mandatory places of jurisdiction in the Consumer’s favour remain reserved. For disputes with professional Buyers, the courts of Lugano have exclusive jurisdiction.

Annex B — NA-48V210Ah sodium-ion battery

Article B1 — Definitions specific to the Battery

B1.1 Nominal Capacity: 10.08 kWh, the value declared in the Battery Datasheet and referring to the conditions of the Measurement Procedure in this Annex.

B1.2 Residual Capacity: the energy delivered by the Battery in the Measurement Procedure, expressed as a percentage of the Nominal Capacity.

B1.3 Reference Measurement: the measurement of Residual Capacity carried out in accordance with the Measurement Procedure and documented in the report provided for therein. It is the only way in which Residual Capacity is determined for the purposes of these conditions.

B1.4 Energy Delivered: the total energy discharged by the Batteries of the System, measured at their DC terminals from the Activation Date, determined and allocated among the Batteries in accordance with Article B5 and expressed in MWh. Energy absorbed during charging is not counted.

Article B2 — Warranty against defects

B2.1 The warranty against defects in Article 4 lasts ten years and covers the cells, the battery management system, the enclosure, the connectors and the internal components supplied by Heiwit.

Article B3 — Performance warranty

B3.1 Heiwit warrants that the Residual Capacity of each Battery, determined by the Reference Measurement, will not be less than 60% of the Nominal Capacity until the first of the following two limits is reached:

• ten years from the start date set out in Article 6;
• 25 MWh of Energy Delivered allocated to the individual Battery in accordance with Article B5.

B3.2 When the first of the two limits is reached, the performance warranty ends, even if the other has not been reached. The limits apply to each Battery separately: in a System with more than one Battery, one of them reaching a limit does not affect the warranty of the others.

B3.3 The Reference Measurement has a declared uncertainty of ± 3 percentage points (Measurement Procedure, point 6). The performance warranty applies when the measured Residual Capacity is less than 57%, i.e. the 60% threshold minus the uncertainty. For values between 57% and 63% the measurement is repeated; if the average of the two measurements also remains within this range, the matter is decided by a test carried out at Heiwit’s expense by a laboratory accredited to ISO/IEC 17025, and the warranty applies if the Residual Capacity so measured is less than 60% (point 7 of the Measurement Procedure).

B3.4 The readings of the battery management system (including state of health, estimated capacity and number of cycles), of the monitoring portal and of user apps are for information only: they are not a measurement of Residual Capacity and do not in themselves give grounds for a claim under this Article.

Article B4 — Measurement of Residual Capacity

B4.1 Residual Capacity is determined exclusively by the Measurement Procedure in this Annex, carried out by personnel appointed by Heiwit using calibrated instruments, at the System or at a laboratory designated by Heiwit. The measurement is carried out with the test parameters of the Procedure, irrespective of the operating settings of the System: changes to the operating parameters under Article 8.3 do not affect the result.

B4.2 The Buyer may attend the test in person or through a technician of the Buyer’s choice. The result is communicated to the Buyer in writing with the report provided for in point 8 of the Measurement Procedure, which also applies to the laboratory test.

B4.3 The measurement is carried out at no cost to the Buyer. If it establishes a Residual Capacity not lower than the threshold in Article B3.3, Heiwit is not obliged to repeat the measurement on the same Battery before twenty-four months have elapsed, unless the Buyer provides new and specific evidence.

Article B5 — Energy count and monitoring

B5.1 Energy Delivered is determined by Heiwit on the basis of the records of the monitoring system, consisting of the Inverter’s cumulative counter and the System’s daily records, referring to the DC terminals of the Batteries.

B5.2 The Inverter’s cumulative counter is authoritative. For periods in which Heiwit documents an anomaly of the counter, such as a reset, the sum of the daily records is used. Any anomalies found and the method used are shown in the breakdown under Article B5.5.

B5.3 The Energy Delivered by the System is allocated in equal parts to the Batteries that make it up, taking into account the period each of them has been in the System. The value so allocated is the one to which the energy limit in Article B3 refers.

B5.4 For periods without records, Energy Delivered is determined by applying the daily average recorded for the same System in the periods covered. If the periods covered total less than ninety days, the conventional value of 5 kWh per day per Battery applies. Periods in which the Battery was out of operation owing to a defect covered by the warranty are not counted.

B5.5 The Buyer is entitled to obtain from Heiwit, at any time and free of charge, the value of Energy Delivered allocated to the Buyer’s Batteries with a breakdown of the records from which it derives, and to challenge it by providing evidence to the contrary. It is for Heiwit to document the value allocated. Heiwit keeps the data required for the calculation for the entire Warranty Period.

B5.6 If the System remains disconnected from the monitoring system for more than six consecutive months and the connection is not restored within sixty days of Heiwit’s written notice stating the consequences, the Energy Delivered for the entire period of disconnection is determined using the conventional value of 6.8 kWh per day per Battery, instead of the average under Article B5.4. Disconnections due to the monitoring system, to communication devices supplied by Heiwit or to a defect in the Product are disregarded. The duration of the warranty is not affected.

Article B6 — Conditions of use of the Battery

B6.1 The conditions of use of the Battery for the purposes of Articles 7 and 13 are as follows:

B6.2 If the System remains inactive for more than six months, the Battery must be recharged to a state of charge between 30% and 60%.

Article B7 — Recommendations for use

B7.1 The following recommendations are not conditions for the validity of the warranty. Failure to follow them does not result in the loss of any right and is mentioned only because it affects the service life of the Battery:

• depth of discharge up to 90% of the Nominal Capacity;
• operating temperature between 15 °C and 30 °C;
• clearances for ventilation in accordance with the manual.

Article B8 — Remedies specific to the Battery

B8.1 Where the warranty applies under Article B3, the repaired or replacement Battery has a Residual Capacity of not less than 80% of its own nominal capacity.

Battery parameters

Measurement Procedure for Residual Capacity

This procedure is the only way in which Residual Capacity is determined for the purposes of Article B3. It is carried out by personnel appointed by Heiwit, at the System or at a laboratory designated by Heiwit.

1. Preliminary conditions

• The Battery is disconnected from service and left to rest for at least four hours before the start of the test.
• The test takes place at an ambient temperature of 25 °C ± 3 °C, stabilised for at least six hours; at the start of the test the cell temperature is within the same range.
• The battery management system firmware is updated to the current version released by Heiwit.
• The following are recorded: serial number, firmware version, date and time, ambient temperature and cell temperature at the start of the test.

2. Reference charge

• Constant-current charge at 42 A (0.2 C) up to the end-of-charge voltage declared in the Datasheet, followed by constant-voltage charge until the current falls below 4.2 A (0.02 C).
• One hour of rest at the end of charging.

3. Measurement discharge

• Constant-current discharge at 42 A (0.2 C) down to the end-of-discharge voltage declared in the Datasheet or until the battery management system intervenes, if earlier.
• The energy delivered is integrated over time for the entire duration of the discharge.

4. Measurement point and instruments

• The measurement is carried out at the Battery’s DC output terminals, upstream of any conversion.
• The instrument is a DC power analyser of class 0.5 or better, calibrated no more than twelve months previously. The calibration certificate is attached to the report.
• The values recorded by the battery management system are logged for comparison but do not contribute to the result.

5. Calculation

The Residual Capacity, expressed as a percentage, is the ratio between the energy delivered during the measurement discharge and the Nominal Capacity of 10.08 kWh, multiplied by one hundred.

6. Uncertainty and operative threshold

The combined uncertainty of the procedure is ± 3 percentage points and takes into account the instrument class, the tolerance on the test temperature and the repeatability of the end-of-discharge point. The performance warranty applies when the measured Residual Capacity is less than 57%, i.e. the 60% threshold minus the uncertainty. A value between 57% and 63% neither confirms nor rules out that the threshold has been crossed and triggers the procedure in point 7.

7. Repetition and laboratory test

If the first result falls within the range between 57% and 63%, the measurement is repeated at least seven days later, under the same conditions. If the average of the two results is below 57%, the warranty applies; if it is equal to or above 63%, it does not apply. If it remains between 57% and 63%, the Battery is tested using this procedure by a laboratory accredited to ISO/IEC 17025, chosen and paid for by Heiwit, which also arranges its transport: the warranty applies if the Residual Capacity measured by the laboratory is below 60%.

8. Report

A report is drawn up for each measurement, stating: serial number of the Battery, Activation Date, firmware version, date and place of the test, ambient and cell temperature, current and voltages used, instrument and calibration certificate reference, energy delivered, calculated Residual Capacity, uncertainty applied and result. The report is signed by the person who carried out the test and, if present, by the Buyer or the Buyer’s technician. A copy of the report is given to the Buyer.

9. Data not accepted as a measurement

The following do not constitute a measurement of Residual Capacity and do not in themselves give grounds for a claim under Article B3: state-of-health readings of the battery management system, values shown by the monitoring portal or user apps, capacity estimates learned by the management system, cycle counters and measurements carried out using procedures other than this one.

Annex I — Virgo and Lybra inverters

Article I1 — Models covered

I1.1 Heiwit-branded Virgo 3K-S, 4K6-S and 6K-S single-phase hybrid inverters and Lybra 6K-T, 10K-T and 12K-T three-phase hybrid inverters.

Article I2 — Duration and scope

I2.1 The warranty against defects in Article 4 lasts ten years and covers the components of the Inverter supplied by Heiwit, including the management software.

I2.2 There is no efficiency or production warranty: the efficiency and power values in the Datasheet are laboratory values within the meaning of Article 5.

I2.3 The meter, current sensors, antennas and other accessories supplied with the Inverter, even in the same package, are Accessories and are subject to Annex A.

Article I3 — Conditions of use of the Inverter

I3.1 The conditions of use of the Inverter for the purposes of Articles 7 and 13 are as follows:

• Photovoltaic side: the open-circuit voltage of the strings, calculated at the lowest foreseeable temperature at the installation site, and the input current remain within the maximum values in the Datasheet for the model; the polarity of the connections is correct.
• Batteries: the Inverter is connected only to Heiwit Batteries or to other batteries listed as compatible in the manual, configured with the correct battery type.
• Grid: the connection, protective devices and grid settings comply with the grid operator’s requirements and Swiss technical rules (the electricity utilities’ WV-CH requirements and the VSE recommendation NA/EEA-CH); the surge protection devices required by the standards and the manual are installed.
• Environment: temperature, humidity and altitude remain within the limits of the Datasheet; the location is suitable for the model’s degree of protection and complies with the ventilation clearances in the manual; the Inverter is not exposed to direct sun or rain where the manual excludes this.
• Corrosive atmospheres: installation in environments with ammonia (for example stables and livestock farms), salt spray or chemical vapours requires Heiwit’s written approval before installation; without approval, the warranty does not cover corrosion damage.

Article I4 — Exclusions specific to the Inverter

I4.1 In addition to the exclusions in Article 13, the warranty does not cover damage resulting from:

• overvoltages or overcurrents on the photovoltaic side due to strings outside the limits of Article I3;
• grid voltage or frequency outside the limits of the Datasheet;
• incorrect grid, battery or operating settings not made by Heiwit, without prejudice to Article 13.3;
• third-party devices connected to the Inverter, such as optimisers, electric vehicle chargers or load management systems;
• interruptions of the monitoring service or of the internet connection that do not affect the operation of the Inverter.

Inverter parameters

Annex A — Heiwit accessories

Article A1 — Products covered

A1.1 Heiwit-branded accessories and spare parts, including: single-phase and three-phase backup switchboards, AC/DC switchboard, meters, current sensors, Wi-Fi, Bluetooth and LAN antennas for the Inverters, connecting cables between Batteries.

A1.2 Products of other brands supplied as accessories, for example routers, are subject to Article 2.5.

Article A2 — Duration

A2.1 The warranty against defects in Article 4 lasts two years, even when the Accessory is supplied in the same package as the Inverter or within a kit. It starts as set out in Articles 6.3 and 6.4.

A2.2 A repaired or replacement Accessory is covered for the remaining period and in any case for no less than ninety days (Article 11).

A2.3 The Buyer’s statutory rights against the seller in respect of defects remain unaffected; for Consumers, the limitation period is at least two years from delivery (Article 3).

Accessory parameters