Twenty-Five Years Is the Ceiling for Electronics Warranties

2026-09-21 original Engineering

I got a consultation request from a certain party. Since it’s a consultation, I can only describe it in the abstract, but roughly speaking, there’s a category of tools where you buy one and use it for a lifetime, and the idea was to turn that into an IoT device: embed a sensor, collect usage data, send it to the cloud, and make it visible both to the person using it and the person making it. The concept is sound, and plenty of areas are already moving in that direction.

It’s sound, but as I listened something kept nagging at me, and I ended up asking myself: how many years is a reasonable product warranty here?

Even by my own standards, that’s not a particularly sharp question.

Still, I asked it because I’ve had the good fortune to see, several times over the course of my work, just how hard it is to put a long-term warranty on an electronic circuit. Put a ten-year warranty on a tool meant to last a lifetime, and by any measure it falls short. But say “thirty-year warranty” and design, procurement, and finance all get turned upside down. That much I know.

I know it, but ask me to explain, step by step, what the industry’s ceiling is in years and why it stops there, and it turns out I can’t, not really. Is it twenty years or twenty-five? Is the limiting factor the components, the regulatory system, or the lifespan of the company itself? I wanted to lay all of that out properly for once, so I looked into it and organized my thoughts.

Where is the industry’s ceiling?

Let me state the conclusion up front: as far as I searched, I couldn’t find a single commercial product that puts a warranty of thirty years or more on the electronic PCB itself. The practical ceiling is twenty-five years, and even that is confined to a narrow corner of the solar power world.

Twenty-five years.

Concretely, there are two cases. One is Enphase’s microinverters, whose IQ8 series carries a limited warranty of up to twenty-five years. It used to be fifteen years, and was extended to twenty-five on the basis of accumulated operating tests exceeding one million hours; the manufacturer itself puts it as “designed to run longer than twenty-five years, but the warranty is twenty-five years.” The other is SolarEdge’s power optimizers, which also carry a standard twenty-five-year warranty. What’s interesting is that within the same system, the power conditioner unit itself is stuck at ten to twenty years — a box carrying a fan and electrolytic capacitors simply cannot claim twenty-five years, and that line runs right through the middle of the product lineup.

In other words, a twenty-five-year warranty is a figure permitted only to a PCB that handles the small amount of power from a single panel, that’s simple enough to be potted in resin and left outdoors, and that contains no electrolytic capacitor, no cooling fan, and no battery.

Warranty and design life are different things

Does that mean there’s no electronic equipment in the world running for thirty years or more? Not at all. It’s just described using a different term — not warranty, but design life. Take submarine optical cable repeaters: they’re built on the premise of securing long-term stability of twenty-five years or more at a depth of eight thousand meters on the seafloor, and they’re required to be more reliable than land-based systems. The fiber itself is rated at around twenty-five years of life, and some units in actual operation have survived past thirty. But that isn’t a promise of “we’ll replace it for free if it breaks” — it’s a matter of probabilistic design, aiming to keep the number of repair-ship dispatches across the whole system down to a handful. The safety instrumentation in nuclear power plants works the same way: it obtains environmental certification against a plant lifetime of forty or sixty years, but that doesn’t mean a warranty card comes attached covering forty years of operation.

Warranty and lifespan wear similar faces but stand in entirely different places.

Where does a long-term warranty break down?

So from here, as a general matter, let’s think through what would actually happen if you tried to embed electronics in a lifetime tool and offer a long-term warranty. I laid out the options I could think of, one by one, and every single one breaks down partway through.

The most straightforward option is probably to push high-reliability design all the way and offer a thirty-year warranty. Replace every electrolytic capacitor with film or ceramic, drop the battery, drop the relays and connectors, pot it in resin and seal it off from the outside world. That’s exactly what the twenty-five-year group does. But strip it down that far and no functionality is left. The moment you mount a wireless module you need an antenna contact point, and given the goal of capturing usage data, you’re going to be touching either a moving part or an opening somewhere. Once you picture the thing sitting not just outdoors but in a kitchen or a bathroom, the whole premise of sealing it completely starts to look shaky.

Then what about deciding five years is fine? At first glance that seems reasonable, and plenty of IoT products actually do this. But the thing it’s attached to is a lifetime tool. Even if the electronics die at five years, the tool itself keeps sitting in the kitchen for another twenty-five. What’s left in the buyer’s hands is a tool that still works but has a dead sensor buried inside it, and every time they look at it they’ll remember the maker’s name. Embedding something that breaks inside something that doesn’t is probably the single worst combination you could choose.

Then make it a swappable module. That’s a fairly sound idea. But can you actually make the same module twenty-five years from now? That’s nowhere near self-evident. Both the microcontroller and the wireless chip will certainly be gone by then. What the submarine repeater world does is called lifetime buy — buying the entire needed quantity up front and letting it sit in a warehouse. But that only works because a single cable needs hundreds of repeaters; tell finance you want to hold thirty years of inventory at consumer product volumes, and they’ll shut it down.

Another option: leave the communication side to someone else. This is the most dangerous of all. NTT DoCoMo’s FOMA began in October 2001 and ended on March 31, 2026. i-mode started even earlier, in 1999. One of the biggest pieces of communication infrastructure in Japan disappeared before even twenty-five years were up. Suppose you did manage to build a PCB with a twenty-five-year warranty — the odds that the protocol, certificates, and servers riding on top of it survive twenty-five years are considerably lower than the odds the board itself survives.

Every path stops partway through.

A case solved at the level of institutional design

And yet there’s a domain in the world that has already solved this problem: gas meters and water meters. The certified validity period for a household gas meter is ten years, for a water meter it’s eight years, and for electricity meters it’s set at ten, seven, or five years depending on type — anything past its expiry can no longer be used for billing or certification purposes. So when the deadline arrives, the whole meter gets swapped out.

In other words, the world solved this by shortening the lifespan of the tool itself to match the electronics.

Water pipes last fifty years. So do gas pipes. But the metering box alone is, by law, pulled out and discarded every ten years. Within long-lived infrastructure, only the part that contains electronics has been carved out as a short-cycle consumable, with the replacement built into the regulatory system itself. This is less a technical solution than an institutional one, and it’s been quietly turning for nearly a hundred years. Looking into this, I honestly thought: that’s clever.

Seen this way, there appear to be only three ways to put electronics into a lifetime object. One is to cut the tool’s own lifespan short to match the electronics, and build replacement into the system. Another is to physically separate the electronics from the main body and make it a detachable add-on. The last is to go all in at the twenty-five-year class and pay the corresponding cost — and this only holds up in domains like solar power and submarine cables, where either the unit price or the unit count is extraordinarily large.

What accelerated testing actually proves

A twenty-five-year warranty is not the result of confirming that something runs for twenty-five years.

Nobody has watched twenty-five years actually pass. The one-million-hour figure Enphase cites as its basis isn’t one unit run for a million hours — it’s the cumulative operating time summed across many units. Twenty-five years comes to roughly 220,000 hours, so, for example, running a hundred units for ten thousand hours — a little over a year — gets you to a million hours. What’s happening there is tightening the confidence interval on a single parameter, failure rate per unit time, by piling up sample size — not an exercise in actually traversing twenty-five years of time. And when you compress time further by raising the temperature, you extrapolate using the Arrhenius equation, but there is no guarantee, in principle, that the extrapolation stretches smoothly all the way out to twenty-five years. If the failure mode switches partway through, the whole extrapolation comes apart.

Let me be clear that this isn’t a claim that Enphase’s methodology is sloppy. If anything, properly accumulating a sample of a million hours and stating it explicitly as the basis puts them among the more honest players in this industry. Accelerated testing plus extrapolation is the only tool available — that’s where reliability engineering currently stands, and it’s the same for everyone.

Which means a long-term warranty figure is, in a sense, entirely a bet.

The other half is accounting and corporate lifespan

Being a bet, the matter drifts away from technology. Offering a thirty-year warranty means taking on the obligation to supply replacement parts for thirty years, and it also means booking thirty years of projected failure rate as a warranty reserve on the balance sheet. On top of that, the company fulfilling that warranty needs to still exist thirty years later. Twenty-five years ago was 2001, the very year FOMA launched, and if you recall the roster of electronics makers that were thriving back then, that tells you something.

Half of a warranty period is a matter of reliability engineering, and the other half is a matter of accounting and a company’s probability of survival. That’s why, no matter how good a board you build, the number thirty simply doesn’t come out.

For what it’s worth, here’s my own answer: if you’re going to put electronics into something meant to be used for a long time, the only option is to build the replacement of the electronics into either the design or the institutional system from the start. Gas meters wrote it into the system. Making it a detachable add-on writes it into the design. Do the opposite, embed it without writing anything in, and twenty years later the world ends up littered with tools that are still perfectly functional except that the sensor inside has quietly died.

References

This piece was drafted and directed by Kuzuryu, with the writing done by AI.

Originally published in Japanese at https://clazytech.com/2026/09/1813/. Translated with LLM assistance and reviewed before publication.