Battery warranty throughput limits

A home battery warranty can end because a set number of years has passed, the battery has completed a stated number of cycles or it has discharged a stated amount of energy. Some warranties use only one or two of these limits. Others add a capacity-retention promise, which says how much usable storage the battery should retain during the covered period.

The exact warranty document matters more than a headline number. Terms change between product generations and sometimes between activation dates, countries and permitted uses.

Time, cycles and throughput are separate limits

A calendar limit runs from the date defined in the warranty. That might be installation, commissioning, activation or a date linked to manufacture. A ten-year headline is not enough to identify the start date.

A cycle limit counts energy discharged in full-cycle equivalents. Two discharges of half the battery’s capacity add up to one equivalent cycle. A warranty that ends at 6,000 cycles does not normally count every small charge or discharge as a complete cycle.

A throughput limit measures the total energy discharged during the warranty, usually in MWh. The time needed to reach it depends on how much energy the battery moves each day. A 30 MWh limit would be reached after 3,000 full 10 kWh discharges, or 6,000 discharges of 5 kWh. Those are arithmetic examples, not estimates of how a particular home will use its battery.

Where a warranty lists more than one limit, it normally states which one takes precedence. Enphase’s current UK warranty for the IQ Battery 5P, for example, ends at the earlier of the applicable time period and the stated cycle limit. Other manufacturers may use different wording and counting methods.

Capacity retention is a performance floor

Capacity retention describes the minimum storage capacity covered at a stated point. It is different from the battery’s state of charge, which changes every day.

Tesla’s European Powerwall warranty, effective 3 December 2025, covers Powerwall 2 and Powerwall 3 for ten years. For units installed in the UK it states 80% energy retention at ten years. The current Enphase UK storage warranty uses a stepped requirement for covered IQ Batteries: 70% at the end of year ten and 60% at the end of year fifteen.

Falling below a retention floor does not automatically determine the remedy. The warranty sets out whether the provider may repair the product, replace it or offer another remedy. It also defines how capacity is measured and which exclusions apply.

Passing a warranty limit is not an instruction for the battery to switch off. It ends or changes the contractual cover. The battery may continue to operate with reduced capacity, but its condition cannot be inferred from the expiry date alone.

The permitted use can change the limit

The same product can carry different limits for different operating modes. Tesla’s current UK terms give unlimited cycles for solar self-consumption, time-based control and backup use. Other applications, or combinations that include an unlisted application, are limited to 37.8 MWh of aggregate throughput. Both routes retain the same stated 80% capacity floor at ten years in the UK.

This is why labels such as “unlimited cycles” need their conditions. Before using a battery for third-party dispatch, grid services or another operating mode beyond ordinary household control, check that the warranty permits it and whether a throughput limit replaces the unlimited-cycle wording.

Registration, connectivity and the installed location

Warranty cover often depends on steps completed at commissioning. The myenergi libbi warranty requires the installer to register the system. Its published terms separate the components: ten years for the battery modules, ten years for the hybrid inverter and three years for the controller.

Tesla requires a Powerwall to be registered and connected so that remote firmware updates can be delivered. Its terms say an extended loss of internet access or failure to register may prevent Tesla from providing the full ten-year warranty, while preserving at least four years subject to the other exclusions.

Other conditions can include installation by an authorised installer, operation within temperature limits, approved repairs and keeping the product at its original location. These are contract terms, so the applicable PDF should be saved with the commissioning and handover documents rather than replaced later by a newer version from the manufacturer’s website.

Useful records include:

• the warranty version and effective date
• the product model and serial number
• proof of purchase and commissioning
• registration confirmation
• installer details
• cycle, throughput and capacity readings available through the monitoring system

Manufacturer failure and the GivEnergy position

A long warranty is only as useful as the organisation responsible for it. GivEnergy Ltd, company number 11571089, entered administration on 9 April 2026 and ceased trading. The appointed administrator has stated that GivEnergy Ltd will honour no further hardware warranties or user and software support. Owners are directed to their installer in the first instance.

As at 22 July 2026, GivEnergy Software Limited was not included in that administration and remained active on the Companies House register. That does not transfer the hardware warranty to the software company. Installed GivEnergy equipment may continue to operate, but the original headline warranty should not be presented as live manufacturer cover.

A manufacturer’s warranty is separate from statutory rights arising from the sale or installation contract. The Consumer Rights Act 2015 includes satisfactory quality, fitness for purpose and durability when assessing goods. GOV.UK guidance says warranty expiry does not by itself remove a customer’s rights against the trader. The route available in an individual case depends on who supplied the equipment, the contract, the date of purchase and the evidence of the fault. Owners dealing with an insolvent supplier or a disputed claim may need individual consumer advice.

Current examples cannot be reduced to one ranking

These examples show why headline years alone do not compare the cover.

Product or system	Published time limit	Other material limit or condition
Tesla Powerwall 2 and 3, current UK terms	10 years	80% retention; unlimited cycles for listed household uses, otherwise 37.8 MWh throughput
Enphase IQ Battery 5P, current UK terms	Up to 15 years	Up to 6,000 cycles; 70% retention at year 10 and 60% at year 15
myenergi libbi	10 years for battery and inverter	Controller covered for 3 years; installer registration required
GivEnergy products	Historical terms varied by product	GivEnergy Ltd ceased trading and its administrator says no further hardware warranties will be honoured

The applicable warranty is the document tied to the product, territory and activation date. A current marketing page is not a substitute for the terms supplied with an existing installation.

Related entries

• Battery firmware and cloud dependency
• Battery end-of-life recycling
• State of charge control
• Time-of-use battery arbitrage
• Usable battery capacity
• LFP battery chemistry