Need somebody to explain something to me about the cold and electrical?

[GassenD]

During the summer my idle voltage is always about 14.2-.4, now that it's cold as balls out my voltage right when I start my vehicle up in the morning is 14.9-15.2 and then stay around 15v while driving.. I've always read that having voltage that high is unhealthy for the electrical but nothing seems to be messing up..

[alaskanzx5]

Basically voltage above 15-15.2 can be bad. Not really in the danger area yet. Now I would consider voltage of 15.5-16v bad for a 12v system myself.

As for why your charging so high

The cold weather creates more power drain, lights, heaters, seat warmers (if you have them), and simply the cold can drain it faster. Its normal for colder weather to increase voltage

[islandpride684]

The colder the weather, the higher the charging voltage will be, same for it being hot but vice versa....normal charging voltage might be 13.9 to 15.1 (13.5 to 14.3 on a hot engine on a hot day) but might jump as high as 14.9 to 15.8 for a short period of time....all depending on the temperature...also like Alaskan said, the load on the vehicles electrical along with the battery's state of charge plays a factor.....

How cold are we talking about? Also, alt and batteries aftermarket?

[GassenD]

Stock alt, aftermarket batteries. And About 20-30 degrees..

[alaskanzx5]

It can also very from car to car. They could be the same years, make, model,engine and alt. That means nothing though. Same amount of running time, temp outside and load but o e may still charge higher or lower then the other. Could be that one gas a slightly better connction, computer working differently, or just because with no real explanation available.

[hispls]

Many people report cars charging a bit high on cold days. Personally I think above 15V is sketchy, but most likely it's only for a short time so shouldn't be long enough to boil your batteries.

[snafu]

Think about the role of the voltage regulator and how it does its job . . .

[alaskanzx5]

The regulator increases charging when it sees a load, or low battery.

When its cold out the engine needs more from the battery to start. Drains the battery more and quicker. On top of that the Col weather affects how well the battery holds a charge. The computer sees this and tells the regulator that it needs to charge things up a bit more. So the regulator turns on and charges at a higher voltage.

You also have the heater going, you have less day light meaning the more use of headlights, heated seats if you have it, heated mirrors as well, and you still have the usual demands of the car.

[SLYentist]

The prime charging voltage difference for lead-acid batteries varies depending on temperature. A battery will not hold a charge, and will take longer to charge in colder temperatures, also the cold air cools the alternator better, causing higher overall system voltage difference. Just the opposite of lover voltages in warmer temperatures. This variance is normal, and as long as the voltage does not reach mid-15s, the sensitive electronics in your car's electrical system should be fine. The only real draw-back is light bulb life is drastically shortened when run at voltages above 15V.

[GassenD]

The prime charging voltage difference for lead-acid batteries varies depending on temperature. A battery will not hold a charge, and will take longer to charge in colder temperatures, also the cold air cools the alternator better, causing higher overall system voltage difference. Just the opposite of lover voltages in warmer temperatures. This variance is normal, and as long as the voltage does not reach mid-15s, the sensitive electronics in your car's electrical system should be fine. The only real draw-back is light bulb life is drastically shortened when run at voltages above 15V.

Speaking of light bulb light I noticed for the first time this year my dome light has been extra bright, could this have anything to do with it.