Well, with a non-TPMS system the valve stem was replaced every time a new tire was installed. It seems reasonable to reseal the sensors with new seals and hardware, under the same line of thinking.
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Capacitors and batteries work on two completely different principles. A battery doesnât store any electrons. A chemical reaction pumps electrons through the battery and the load. The flow of electrons allows the chemical reaction to occur. In some batteries, reversing the flow of electrons reverses the chemical reaction.
No chemical reactions occur in the charging or discharging of a capacitor.
First of all, there is already a sensor in the wheel so forget about any additional parasitic losses because they are already there, even though they are MINUSCULE compared to the energy being lost elsewhere. I would challenge anyone to actually measure such a thing although one could calculate it.
The changes I suggest are not going to add any weight to the existing assembly, it would likely be a wash. Batteries are relatively heavy compared to the parts used in an alternative approach.
A super cap will outlive everyone on this board and likely our offspring. How long does a battery last when it has no way to be recharged? If youâre going to recharge in a captive environment, a cap is a better choice anyway.
The power required for this application is in the NANOwatts. How long do you think those batteries would last if it required more power? Done correctly, this is also not a constant power draw. The sensors should go to sleep when the car is not active. They only need to pulse out data at a periodic rate when the car is active. Using this approach, sensors in most peopleâs cars will last many years even with a battery. But think about all the commercial vehicles that are far more active. They may need sensors at a much higher rate. Regardless, no one I know replaces these sensors proactively. They fail and then they are replaced. The batteries cannot be exchanged because they are encapsulated in a potting compound to make them hermetically sealed and also eliminate issues from G forces. So itâs usually an inconvenience to replace them when they do exhaust the batteries and youâre throwing away the remainder of the unit which is still functional.
Letâs look at overall cost of ownership. Even if the sensors cost $10 more per sensor (which I think is unrealistic but given here as a worst case just for the sake of argument) thatâs $40 more than you pay now. BUT, they more than pay for themselves compared to swapping out the current sensors only one time in the life of the car. And youâre not inconveniencedâŠ
Yes. It does. If it didnât there wouldnât be a charge there to start the car. Both sides of the plates would be the same potential.
Itâs true that no chemical reactions occur in a capacitor. However I wasnât describing the differences between the two, I was describing the similarities.
Capacitors have plates, batteries have anodes and cathodes.
A completely dead battery contains just as many electrons as a fully charged battery. In case you havenât noticed, there are two wires going to a battery, one where electrons leave the battery, and the other where they return. If those electrons canât return, the circuit is open and the battery does nothing.
There is no net gain or loss of electrons when a battery is charged or discharged.
To be technically correct, itâs a voltaic cell, not a battery. A battery is a bunch of cells ganged together to increase the voltage. A car battery is actually a battery of cells, just like a fortress or a ship might have a battery of guns. Battery Park in NYC has nothing to do with electric batteries, but was named after an artillery battery that was once placed there to defend the harbor.
And exactly how much use is a capacitor with only one lead? Unless, of course, itâs a surface mount device.
Iâm not going to argue this with you. We totally disagree on this. Both capacitors and batteries store more negative (more electrons) polarities on one side of a dielectric and relatively less on the other side. They simply do it in a different media.
But please, donât talk down to me as if I donât know how a battery is constructed or what the term âbatteryâ means. Itâs insulting. And itâs a word game.
We disagree. End of debate.
My 2010 Kiaâs valve stems were replaced in October for a recall. The work order included 4 TPMS kits. I should be good for awhile. No charge for anything.
TPMS sensors drive many owners nuts. Iâm pretty passionate about the subject and penned this story at BestRide explaining the options to sensors in every wheel. While I see the benefits, the negatives are real as well. That said, I donât consider them a maintenance item in need of replacement at any set interval, like cars that have timing belts.
Pray tell, exactly what is the dielectric in a battery?
Another poossibility: a TPMS sensor that gets itâs power from an RF signal generated outside the tire, like RFID chips on credit cards.
No battery or other power source needed inside the tire.
Another one of those rude surprises customers get when buying vehicles . . by looks or monthly payment !
Tires and rims are always a big one here when they find their 45 series tires are over two hundred each. And forget it when they curb a wheel and need one of those ââprettyââ wheels that drew them to this car and not that one.
- Even just a ''tune up ââ these day results in sticker shock.
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I mentioned wireless charging in the first post. A simple planar coil on either side makes an air core transformerâŠPhone guys making big deal of this now but itâs been around for a LONG time. Some time back I suggested they might be able to charge cars like that and eliminate the cabling aspectâŠ
We have a planar transformer design in one of our products that can achieve very high efficiency regardless of various factors- distance, interference, parasitic losses etc.