Why do batteries die in the cold?


It was cold this morning!  I recorded -4F at about 7 am!  I drive a diesel truck with 2 batteries and even then my truck cranked over slower than normal.  But why does cold affect batteries?  Why is it that when I have to replace my battery, it’s usually cold out?

Cold affects the chemical magic that happens inside a battery.  When the battery temperature drops, the chemical reaction that takes place inside your battery can’t work as efficiently.  This causes your battery’s electrical output to be as much as 1/2 the output it would be if the battery is warm.  This also answers another question I hear from my customers a lot. It deals with the cranking amp rating of the battery.

The average car only requires about 150 amps give or take to operate the starter.  So why on earth would we need to install a battery capable of producing over 600 amps?  For one thing, what we talked about earlier.  In very frigid temperatures and brand new battery rated at 600 amps may only be able to produce 300 amps.  So there is 1/2 the capacity right there.  The second thing is as batteries age, their ability to produce power declines.  In order for your battery to give acceptable starting power in all temp ranges and last more than a few months, they have to be able to produce many times the amount of electricity required by your car when they are new as this number will only drop as time goes on and temps go down.

So what are some ways a battery can fail and what can be done to maximize the life of a battery?  Glad you asked!  First and foremost, don’t let the battery die.  Batteries are made up internally of lots of lead plates placed in close proximity to each other submerged in an electrolyte.  It is critical that these plates do not physically touch each other.  When they do, the battery becomes weaker and weaker the more of them that touch.  When the battery dies, this allows sediment and corrosion to form inside the battery and this can actually cause the plates to bridge together accelerating the demise of the battery.  If your battery dies for any reason, charge it back up asap.

Don’t let the electrolyte level get low.  Batteries depend on electrolyte for the chemical magic to occur.  Some batteries have removable caps on the top that can be removed for electrolyte inspection and level adjustment.  If electrolyte must be added, use clean distilled water.  Some batteries do not have these caps and are sealed for life.

Keep the battery terminals clean and tight.  Loose terminals and poor connections create heat.  This heat easily transfers to the battery terminal and can cause the plastic battery case to distort around the terminal and allow electrolyte to leak.  This is what causes that blue or white fuzz to grow on your battery cable connections.  If this happens, it’s best to replace both the battery and the cable terminals.

Have your battery tested at LEAST once a year and better yet at every service interval.  We have equipment that can detect a weak battery before it leaves you stranded.

If the cold got your battery, we have top quality Interstate batteries in stock and ready to install!  Visit our website for more information!  You can also find us on facebook!

Leave a Reply