Five years? Why not fifty? Or a hundred?
What you're actually asking for is something like a service contract where, as long as pay the premiums, they undertake to fix any flaws. But I'll bet the take-up ratio of that sort of model would be very low, because the consumer wants a cheap gadget, and the fact that you want the vendors to be liable for some indeterminate amount of work for however long you want them to be liable will have a predictable effect on the price (hint: upwards). So does the average punter want to pay for what you want them to have, or what they are OK with getting?