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Old Tue, January 27th, 2009, 02:36 PM
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Jackpine Jackpine is offline
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Location: Among Elk, Deer and Javalinas on the Mogollon Rim in Aridzona
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Quote:
Originally Posted by Chris74 View Post
Jack: How much of an impact does cold weather have on these figures?
My truck is an FX4......doesn't have quite as many bells and whistles as yours but does have 6 disk changer, power seats, etc. I left my truck for exactly 7 days (with gryphon plugged in) in covered parking lot and average temp during that time was -25c or -13F and battery didn't have enough juice to even roll starter.
Another funny thing is.......when I put key in the ignition things started to go wonky as well. The CD player started screwing around with the discs. It's like it couldn't remember which disc was supposed to be in which of the 6 slots. I'm surprised the digital clock was even able to keep the time - it was so :censored3: cold!
I really can't say what the effect of cold weather is except that it's bad. Batteries produce electricity through a chemical reaction between the electrolyte and the plates. Cold temperatures slow this reaction down, which means less power available for starting (which is when you really need it). The starter, as you know, pulls a relatively HUGE amount of current and even a moderately discharged battery can supply that current when it's warm, but put the same battery in cold and there's just not enough power producing capability available. If it's cold enough, even a fully charged battery will act like it's dead.

Batteries aren't even rated at -13F. The Cold Cranking Amperage (CCA) rating is how many amps the battery can supply for 30 sec at 0F without the voltage going below 7.2V. Cranking Amps (CA) are measured for 30 sec at 32F and this figure is quite a bit higher.

I've seen the same wonky behavior in my CD changer after pulling and then resetting the CD player fuse. At first I thought I'd broken something. It cycled through all disk positions. Clocks seem to do pretty well though, as long as there's just a little bit of power.

I don't have any good solutions for those of you in cold climates except try to make sure your battery is healthy and always carry good (6 gauge minimum) jumper cables. If I was in a cold climate and I started seeing corrosion on either of the terminals (which is a sign of gassing) or if the electrolyte dropped in any of the cells, I'd replace the battery.

- Jack
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