Hardcore Rock Superstar

iTrader: (2)

I always keep an eye on my battery charge guage...cause generally it's pretty accurate.

I've noticed in the summer when it's warm, it's always lower. If we get a nice cold day, it'll be above the mid way mark.

Whats the reasoning behind this if there is one? Not like i have AC or anything which uses the power/alternator

Jboy2

iTrader: (3)

Yea, i found out this with my astro, i just think becuase its colder and the engine workers harder to become warm... which tranlates to better voltage.

Iunno tho

Killer_klown187

iTrader: (20)

I would like to know the Technical behind this! One theory behind I have, Metal is smaller when cold so the contact inside the alternator would be alot closer, and when it all heats up(engine heat mainly) Metal expands!!! making it not have such a close contact patch persay! but this is just what I remember from school, (metal heat and cold) If anyone else can expand further! greatly appreciated! In my lancer when its cold, I charge at 15.1, when warm 14.5 floating that will be soon to change but for now its kind of neat!

Riddle_Rob

iTrader: (4)

Also, if you notice when you're car is cold it tends to idle a bit higher trying to warm up and with a higher idle, means higher rpm, and belt spins faster so yeah... i dunno thats my thoughts?

MrEastSide

I used to notice the same thing on my old Camaro. The meter would be near middle during the summer, and in the winter when it would just be freezing, the meter would spike to almost the top. My Explorer didn't seem to have such a huge gap in different temperatures. But, the Camaro would almost go off the gauge when it would get cold out.

JohnVroom

I am not sure how accurate the meter in question is BTW ... but to answer the question, everything electrical in your car will be more efficient cool than hot (with the exception of the battery which is not electrical it is chemical it produces more power hot (CA vs CCA ratings illustrate that)).

zinger002

iTrader: (1)

when electrical energe gets converted to any form of heat there is a loss. when it is cold and your alt is cool the voltage produced is higher.

you may also notice when your car starts the voltage is higher then drops off as your car heats up.


and also in order to change the magnetic feild by heating and cooling the components in your alt to get them to shift farther apart... i dont think the metals can expand far enough to shrink the magnetic feild enough to really change the output of your alternator. even half an inch is not going to e a huge drop, plus i dont think the metals and components can even expand that far.