I think it's normal that they fail after a period of time. My truck and motorcycle sensors failed at around ten years. The sensors have a standard coin-style battery that can't possibly hold a charge indefinitely.
Makes sense. But given all the energy going into a wheel (making it spin!), you'd think some simple transducer could be arranged to just keep the damn things charged. Replace battery with supercapacitor, and voila... Never-die TPMS sensors!
If you can design it, that sounds like it would make you filthy rich!
No need. If RFID style TPMS's can't handle the application by harvesting energy off the transmission signal from an RFID transmit module in the vehicle to re-transmit their data, it you could harvest energy just off the rotation of the wheel itself, the way electric self-winding wrist watches have been recharging themselves since the 1970's.
lol...
I have also seen where the sensor will occasionally start working again for a bit. I suspect that the heat from the tire can warm the battery enough to make it temporarily work again.Apparently one sensor is bad on my new Kia. I should have it checked under warranty. All tires exact same pressure and the spare, but light came on dash. I left car battery disconnected 24 hours and turned headlights on to bleed off any charge...but light still on.
Finally went off after about 50 miles.
Ironic, in this post. Here vs hear.
In defense of the typo's, I routinely find the wrong "their, there, they're" or "its, it's" in my own posts, despite knowing very well which (witch) to use! My excuse is that I'm just blasting out a post as quickly as possible, often on a tiny screen, this is hardly a forum for peer-reviewed and edited papers.
Ha. Me too. Fat finger syndrome here. I often go back, read my post and edit it.
I suspect it's the time, more than the mileage. I've kept one or two cars past 140k miles, we used to have long commutes that would really rack up a lot of miles fast. But I don't think I've ever owned a vehicle as old as 14 years, since they started coming with TPMS's, which might explain why I've never seen this.
HAHAHA!
I stand corrected!
Actually a good idea and free power. For many years small gas motors have used induction for charging and ignition via magnet(s) in the flywheel and magneto coil outside for spark and coil inside for battery charging. Totally free power that could be utilized.
It wasn't free power. The engine had to work harder to produce that spark. It was miniscule, but it wasn't free. It's no more free than electricity created by an alternator turned by a belt on the engine. It reminds me of when I worked at a subsidiary of GM and was sitting in on a patent review meeting. An engineer suggested putting a mini windmill on the hood to generate "free" electricity. An engineer who presumably passed at least one thermodynamics class in college. I thought he should have been fired for incompetence.
Yep... nothing is free, in science and theory. But in Fuddy's defense, when you start adding up the practical dollars and cents of competing solutions, then it can indeed be considered nearly "free" to the engineers and bean counters.
