Warranty conditions

• General section
• Annex B — NA-48V210Ah sodium-ion battery
• Annex I — Virgo and Lybra inverters
• Annex A — Heiwit accessories

Foreword

Heiwit S.p.A., with registered office at Via Carlo Robbioni 2, 21100 Varese (VA), VAT No. 03980400125 (“Heiwit”), markets under its own brand sodium-ion battery electricity storage systems, inverters and accessories. These conditions govern the commercial warranty that Heiwit, as manufacturer, grants to the Purchaser on the products listed in Article 2.

These conditions consist of a general section, 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, 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 granted to the Purchaser by law, without replacing or limiting them (Article 3).

General section

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 its product code and the purchase document.

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

1.3 Purchaser: the natural or legal person who purchases the Product for end use through an Installer of the Heiwit network. A Consumer is a Purchaser who is a natural person acting for purposes unrelated to any business, commercial, craft or professional activity they may carry on.

1.4 Installer: the business belonging to the Heiwit network that installed the Product.

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

1.6 Activation Date: the date on which the Product was commissioned, as shown by the registration referred to in Article 6.

1.7 Shipping Date: the date on which Heiwit shipped the Product to the Installer or distributor, as shown by Heiwit's transport documents.

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

1.9 Reference Price: the lower of the price of the Product shown separately on the Purchaser's purchase invoice and Heiwit's public list price in force on the Activation Date, in both cases excluding VAT and installation costs. If the invoice does not show the price of the Product separately, the list price applies.

1.10 Warranty Period: the duration stated in the Annex for the Product, running from the start date set out in Article 6.

1.11 The definitions specific to the Battery (Nominal Capacity, Remaining 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 through the Heiwit installer network and installed in a State of the European Economic Area or 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 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.

2.3 Products of other brands sold by Heiwit, including within a kit — for example PV modules and routers — are covered by the warranty of their respective manufacturer, on that manufacturer's terms. Heiwit neither extends that warranty nor assumes it as its own, and assists the Installer in making the claim to the manufacturer. In a kit, each component is subject to its own warranty.

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

Article 3 — Statutory rights of the Consumer

3.1 The Consumer is entitled by law, free of charge, to remedies against the seller — as a rule the Installer from whom they purchased — for any lack of conformity of the Product, in accordance with Articles 128 et seq. of the Codice del Consumo (D.Lgs. 6 September 2005, no. 206). Those remedies are not affected by this commercial warranty, which is in addition to them.

3.2 No clause of these conditions may be interpreted as excluding, reducing or making subject to conditions the rights granted to the Consumer by law, or the manufacturer's liability for damage caused by defective products.

Article 4 — Warranty against defects

4.1 Heiwit warrants that the Product is free from defects in materials and workmanship for the duration stated in the relevant Annex: ten years for the Battery and the Inverter, two years for the Accessories, running from the start date 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 Heiwit's information materials — including capacity, number of cycles, depth of discharge, efficiency, power and switchover time when the grid is unavailable — are obtained in laboratory tests, under the conditions stated next to 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 everyday use may be lower than the nominal values and may 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 the Remaining Capacity, which is determined solely by the Reference Measurement.

5.3 Heiwit does not guarantee any financial or energy results of the System, such as the output of the PV modules, savings on energy bills, the self-consumption rate, the payback period of the investment or access to incentives.

5.4 Statements made by Installers or by any party other than Heiwit do not modify or extend this warranty.

Article 6 — Registration and start date

6.1 The Products are registered by the Installer at the time of commissioning; the registration includes: serial numbers, Activation Date, address of the System, Installer details and Purchaser details.

6.2 The Purchaser is under no obligation to register; failure by the Installer to register, or late registration, does not prejudice the Purchaser's rights.

6.3 The Warranty Period starts on the Activation Date and in any case no later than six months from the Shipping Date. If no Activation Date has been registered, it runs from the date of the Purchaser's purchase invoice, again within the same limit; if that is not available either, from the sixth month following the Shipping Date.

6.4 For Accessories purchased separately, including as spare parts, the Warranty Period runs from the date of the purchase invoice or, failing that, from the Shipping Date.

6.5 Heiwit notifies the Purchaser of the start date together with the registration confirmation, where it has the Purchaser's contact details, and in any case at the Purchaser'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 set out 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 is installed by an Installer of the Heiwit network, in accordance with the manual and the technical standards of the place of installation; removal and reinstallation are carried out in the same way. The warranty does not cover defects and damage caused by installation, removal or reinstallation carried out by others.

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

Article 8 — Monitoring, updates and operating parameters

8.1 The Purchaser keeps the System connected to the Heiwit monitoring system via their own internet connection: the connection is used for remote diagnostics and updates. For the Battery, prolonged disconnection has the consequences set out in Article B5.6.

8.2 The Purchaser allows 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 remotely change the operating parameters, such as power, temperature and state-of-charge limits. If a change appreciably reduces the energy or power available in operation, Heiwit informs the Purchaser before applying it, stating the reason.

8.4 The warranty does not cover damage directly attributable to the Purchaser's refusal of a corrective update notified in writing by Heiwit with an indication of the consequences.

Article 9 — Warranty claims

9.1 The claim is submitted to Heiwit, normally through the Installer. The Purchaser may in any case contact Heiwit directly by writing to [email protected] or by calling 0332 1730555, in particular where the Installer is no longer operating or does not follow up the claim.

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

9.3 The claim contains: 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 obtained by Heiwit from the monitoring system; the Installer attaches them when the System is not monitored. Heiwit may request a copy of the purchase invoice and of the installation's conformity documentation required by the regulations of the place of installation (in Italy, the declaration of conformity under D.M. 22 January 2008, no. 37).

9.4 In the event of anomalies that may pose safety risks — including overheating, odours, smoke, deformation of the enclosure or system alarms — the Purchaser stops using the Product, has it taken out of service by the Installer and does not open or tamper with it.

9.5 Heiwit assigns the claim a case number, which it communicates to the Purchaser and the Installer. If any necessary documents are missing, it 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 receipt of the complete claim. If a time limit cannot be met, Heiwit informs the Purchaser, stating the reason and the new date. If the remote check is not conclusive, Heiwit arranges an on-site visit by the Installer or an appointed technician and, where the complaint concerns the capacity of the Battery, the Reference Measurement. The Purchaser allows access to the Product on the days and at the times agreed.

9.6 The repair or replacement of a Product found to be defective takes place 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 will, at its discretion, repair the Product or replace it with a new or refurbished Product. The replacement Product is of the same model or, if that model 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 Purchaser agrees, Heiwit grants the residual value of the Product instead. In respect of a Purchaser 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 the Accessories).

10.4 The granting of the residual value extinguishes the warranty on the Product to which it refers. The total amounts granted 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 Battery-specific rules in Article B8, are the only remedies provided under this commercial warranty; the statutory rights in 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 not less than 360 days for the Battery and the Inverter and ninety days for the Accessories, from the date of the 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 service

12.1 For interventions accepted as covered by the warranty and authorised by Heiwit, Heiwit bears the labour and travel costs of the Installer or the appointed technician and the cost of transporting the defective Product and the replacement Product. No cost is borne by the Purchaser.

12.2 Heiwit does not reimburse costs incurred without its written authorisation, nor extraordinary costs of accessing the Product, such as building works, scaffolding or lifting equipment, arising from a location that does not comply 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.

12.4 If the check establishes that the claim is not covered by the warranty owing to one of the grounds for exclusion, or that the Product does not correspond to the one stated in the claim, Heiwit may charge the Purchaser the costs of travel, transport and inspection, provided that it has notified the Purchaser of the amount before the intervention.

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 standards;
• 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 indicate as compatible;
• use of the Products as part 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 Purchaser;
• lightning, overvoltages, fires of external origin, flooding, water ingress, earthquakes and other natural events or force majeure;
• vandalism, theft, malicious damage, animals;
• faults in components of the electrical or PV 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 non-compliant installation, configuration or storage is attributable to an Installer of the Heiwit network, Heiwit nevertheless provides the Purchaser with the assistance set out in these conditions and settles the matter directly with the Installer.

13.4 When it rejects a claim in whole or in part, Heiwit states in writing the reason and the technical evidence on which the rejection is based. The Purchaser 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 Purchaser or a technician of their choosing.

Article 14 — Limitation of liability

14.1 To the extent permitted by law, and except in cases of wilful misconduct or gross negligence, personal injury and liability for damage caused by defective products, 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 energy bills, loss of incentives 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 within sixty days of the transfer.

15.2 The transfer neither renews the Warranty Period nor resets the count of the Battery's Energy Delivered. A Product removed from the original System and reinstalled elsewhere remains covered if the reinstallation is carried out by an Installer of the Heiwit network 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 for the performance of the warranty, and retained for the entire Warranty Period, in accordance with the privacy notice available on heiwit.com.

Article 17 — Final provisions

17.1 This Edition 3 replaces Edition 2 of 16 October 2026, compared with which it is more favourable to the Purchaser, as it permits up to six Batteries in parallel on a Lybra Inverter (Article B6.1), and applies to Products purchased by the Purchaser from 22 October 2026. Subsequent editions do not apply to Products already purchased. Products purchased before 22 October 2026 are subject to the warranty conditions in force at the time of purchase, a copy of which Heiwit provides on request to [email protected]; for those Products, Heiwit nevertheless permits connection to a Lybra Inverter as provided for in Article B6.1 of this Edition.

17.2 The Installer gives the Purchaser a copy of these conditions, on paper or on another durable medium, no later than on delivery of the Products. The conditions are also available on heiwit.com.

17.3 These conditions are drawn up in Italian; in the event of translation, the Italian text prevails.

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

Article 18 — Governing law and jurisdiction

18.1 These conditions are governed by Italian law, without prejudice to the mandatory consumer protection rules of the country in which the Consumer has their habitual residence.

18.2 For disputes with Purchasers acting as Consumers, the court of the Consumer's place of residence or domicile has jurisdiction. For disputes with professional Purchasers, the Court of Varese has exclusive jurisdiction.

Annex B — NA-48V210Ah sodium-ion battery

Article B1 — Battery-specific definitions

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 Remaining 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 the Remaining Capacity carried out in accordance with the Measurement Procedure and documented in the report provided for therein. It is the only way in which the Remaining 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 Remaining 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 attributed 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 Remaining 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 Remaining 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 the user applications are for information purposes: they are not a measurement of the Remaining Capacity and do not in themselves constitute grounds for a claim under this Article.

Article B4 — Measurement of the Remaining Capacity

B4.1 The Remaining 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, regardless of the operating settings of the System: changes to the operating parameters under Article 8.3 do not affect the result.

B4.2 The Purchaser may attend the test in person or through a technician of their choosing. The outcome is communicated to the Purchaser 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 Purchaser. If it establishes a Remaining Capacity not lower than the threshold in Article B3.3, Heiwit is not required to repeat the measurement on the same Battery until twenty-four months have elapsed, unless the Purchaser provides new and concrete evidence.

Article B5 — Energy count and monitoring

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

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

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

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

B5.5 The Purchaser is entitled to obtain from Heiwit, at any time and free of charge, the value of the Energy Delivered attributed to their Batteries, with a breakdown of the records from which it is derived, and to challenge it by providing evidence to the contrary. The burden of documenting the attributed value lies with Heiwit. Heiwit retains the data needed 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, which states the consequences, then for the entire period of disconnection the Energy Delivered is determined using the conventional value of 6.8 kWh per day for each 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 a period of more than six months, the Battery must be recharged to a state of charge of between 30% and 60%.

Article B7 — Recommendations for use

B7.1 The following guidelines are not conditions for the validity of the warranty. Failure to observe them does not result in the loss of any right and is pointed out 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 — Battery-specific remedies

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

Battery parameters

Remaining Capacity Measurement Procedure

This procedure is the only way in which the Remaining 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 at rest for at least four hours before the start of the test.
• The test is carried out 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 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 taken 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 quantities measured by the battery management system are recorded for comparison purposes but do not contribute to the result.

5. Calculation

The Remaining 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 operational 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 Remaining Capacity is less than 57%, i.e. the 60% threshold minus the uncertainty. A value between 57% and 63% does not make it possible either to confirm or to rule 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 less than 57%, the warranty applies; if it is equal to or greater than 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 Remaining Capacity measured by the laboratory is less than 60%.

8. Report

A report is drawn up for each measurement, stating: Battery serial number, 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 Remaining Capacity, uncertainty applied and outcome. The report is signed by the person who carried out the test and, if present, by the Purchaser or their technician. A copy of the report is given to the Purchaser.

9. Data not accepted as a measurement

The following do not constitute a measurement of the Remaining Capacity and do not in themselves constitute grounds for a claim under Article B3: state-of-health readings from the battery management system, values shown by the monitoring portal or by the user applications, 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 Single-phase hybrid inverters Virgo 3K-S, 4K6-S and 6K-S and three-phase hybrid inverters Lybra 6K-T, 10K-T and 12K-T, under the Heiwit brand.

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 No efficiency or production warranty is provided: the efficiency and power ratings in the Datasheet are laboratory values in accordance with Article 5.

I2.3 The meter, current sensors, antennas and other accessories supplied with the Inverter, including 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:

• PV side: the open-circuit voltage of the strings, calculated at the minimum foreseeable temperature at the place of installation, and the input current remain within the maximum values in the model's Datasheet; the polarity of the connections is correct.
• Batteries: the Inverter is connected only to Heiwit Batteries or to other batteries indicated as compatible in the manual, configured with the correct battery type.
• Grid: the connection, protections and grid settings comply with the technical rules of the grid operator and of the country of installation (in Italy, the CEI 0-21 standard); 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 directly exposed to sun or rain where the manual rules this out.
• Sea and corrosive atmospheres: installation less than 500 metres from the coast, or in environments with salt spray, ammonia (for example stables and livestock farms) or chemical vapours, requires Heiwit's written approval before installation; without approval, the warranty does not cover corrosion damage.

Article I4 — Inverter-specific exclusions

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

• overvoltages or overcurrents on the PV 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 back-up switchboards, AC/DC switchboard, meter, 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 2.3.

Article A2 — Duration

A2.1 The warranty against defects in Article 4 lasts two years, including where the Accessory is supplied in the same package as the Inverter or within a kit. The start date is that set out in Articles 6.3 and 6.4.

A2.2 The repaired or replacement Accessory is covered for the remaining period and in any case for not less than ninety days (Article 11).

A2.3 For the Consumer, the statutory remedies against the seller for any lack of conformity that becomes apparent within two years of delivery remain unaffected (Article 3).

Accessory parameters