Cold Temperature VS Your Batteries: What To Know

With winter and lower temperatures coming soon, it brings to mind one of the most often overlooked, and incredibly important questions we face when it comes to caring for our batteries. Does the temperature of my work environment actually have a negative impact on my batteries? Well, the short answer, is yes.

Did you know that battery capacity (in simple terms, how long your battery will last) is actually reduced in cold temperatures, and goes up in warmer climates? A good example of this would be when your car battery dies on a cold winter morning, even though it worked fine the previous afternoon. The effects of temperature on your batteries can actually be quite significant.

The ideal battery environment has a room temperature of about 75 degrees Fahrenheit, or 25 degrees Celcius. When a battery manufacturer states the rated capacity of their batteries, it's almost always stated at this ideal temperature. Rarely, if ever, will a battery manufacturer publish the rated capacity of a battery at these lower temperatures.

Why Low Temperatures Reduce Battery Capacity

Electrolyte viscosity and resistance are increased as the temperature of the electrolyte drops. For instance, take a fully charged battery with a specific gravity of 1.275. In ideal conditions where the room temperature is 75 degrees Fahrenheit, you can expect to get 95% to 99% capacity out of the battery. Now, if you drop the room temperature to 32 degrees Fahrenheit, the battery would only deliver around 75% of its capacity. In certain extreme cold storage applications, where the temperature is 0 degrees Fahrenheit or lower, delivered power can be as low as 40%.  

A good thing to take away from this, is that Batteries should always be kept fully charged in cold weather. In addition to the discharge related problems mentioned above, the charge acceptance of a lead-acid battery is impaired when electrolyte temperatures drop below 60 degrees Fahrenheit. They should be heated, even during storage. If exposure to cold temperatures is severe enough when the battery is discharged, the electrolyte can freeze, which will cause larger problems when it comes times for the battery to be used.

High Temperatures Will Reduce Battery Life

On the other end of the spectrum are high temperatures, and while high temperatures don't have a direct influence on available battery capacity, over time they will diminish the battery life.  Chemical reactions are accelerated at high temperatures causing the rate of corrosion of the positive grid to increase and causing the active material on the plates to shed more rapidly. Shedding can even eventually create a short circuit in the cell, severely impacting your battery.

Electrolyte temperatures above 90 degrees Fahrenheit. will cause some reduction in service life and should be avoided whenever possible. Never allow cell temperatures to exceed 110 degrees Fahrenheit over extended periods of time, as this will cause damage to the cells within your battery.

Now, that isn't to say that if you were running a battery all day, or if it's fresh off of charge, that it shouldn't be warm. However, if your battery if boiling hot, there's a problem and it should be brought up to your battery care experts to make sure there is not a larger issue.