How can the PCB inside our car remote sustain -20 deg. C weather?

[Happy Hopping]

for car manufacturers charging us $100+ for car remote replacement, how does the PCB inside able to sustain -5 deg. C or lower for the whole winter, year after year? in any PCB that we handle, there is a manual that says operating temperature around 5 to 40 deg. C.

So when we uses these keyless entry, doesn't that drastically cut down the life span of the remote? I have car that allows me to turn the key with an actual key, but there are cars out there that there is no key hole, you have to use the remote.

IF that remote dies, you're in the middle of the street, what do you do?

 

[Zepher]

my keyfob is usually in my pocket, so my clothes and body heat keep the fob warm.

The ECU in the car on the other hand is out there freezing and still seems to work fine.

 

[Happy Hopping]

so is mine, but hwen you walk to the parking lot at the grocery store, you still have to dig it out of your pocket and press that button

 

[Zepher]

so is mine, but hwen you walk to the parking lot at the grocery store, you still have to dig it out of your pocket and press that button

whipping it out like that won't have much affect on the temp.

 

[Happy Hopping]

1) firstly, we explore it ongoingly day in , day out, so there is an ammulative effect

2) you could use that argument w/ human hand, I wear gloves, and there is almost no exposure to outdoor, and yet, my skin already crack due to weather.

 

[cyclone3d]

Well... to put it simply different electronics are designed to work at different temperature ranges.

-20C is NOTHING. what about space probes that have been operating for decades now?

Some of the components of a Mars rover have to be kept in the -40C to +40C range.
https://mars.nasa.gov/mer/mission/rover/temperature/

But there are electronics components that can operate at lower and higher temperatures than that.

Good capacitors have a 105C rating though keeping the temperature lower will extend the life of them.

And extreme overclockers use such things as liquid Nitrogen which evaporates at -196C to cool CPUs and GPUs.

As far as a car remote, there is really no expansion/contraction of the components due to the minuscule amount of power used by the remote itself so you aren't going to have to worry about stress fractures from cooling / heating cycles.

Really.. heat is the killer for electronics. cold, in and of itself really doesn't hurt electronics. It is condensation forming on those components from temperature differentials and that condensation having impurities which can make the condensation electrically conductive or leave deposits which can short out electronics components.

If you take apart the ECU for a vehicle, you will find that everything will most likely be encased in a type of epoxy compound. Part of the reason is to keep out condensation and liquids. It also insulates the ECU so it will not be susceptible to large temperature swings from external sources.

Those ECUs go through a whole lot of testing before they are validated for production... such as environmental chambers that make sure they will keep working pretty much no matter what. The components used in them are designed to handle what they need to handle and keep working.

Batteries will not be able to put out as much power when super cold, which is why when your car battery is weak and the weather turns cold it may not be able to start your car. This is also why the batteries have an amperage rating as well as a CCA (cold cranking amps) rating.