Hello Duke here and welcome to Allied Auto Works. Today I thought we would create some energy and focus on batteries. It seems like everything in Los Altos runs on batteries. Of course, the batteries we're most concerned with here at Allied Auto Works are those in our customer's vehicles. So let's get some static and start barkin' on this electrifying subject!
Just like the batteries in our smoke detectors or TV remote, 
they wear out and need to be replaced. This can be thought of as the power output used to start a cold vehicle engine. The number of cold cranking amps you need depends on your vehicle and where you live in CA, specifically how cold it is. (Many Los Altos drivers have first-hand experience trying to start their car on a cold winter morning.) The two factors are that the colder your vehicle's engine is, the more power it takes to turn the engine over to get it started. It has all that cold, sluggish oil to contend with.
The other factor is that the chemical reaction in the battery that creates electrical energy is less efficient when the temperature dips. Let's say it's 80 degrees Fahrenheit (27 degrees C) in Los Altos. At that temperature, 100% of the battery's power is available. At freezing, only 65% of battery power is available, but it requires 155% as much power to start the engine as it did at 80 degrees F (27 degrees C).
As you can see, the colder it gets, more power is needed, but the available power drops.
So if you live where it's cold in CA, you need a battery with more cold cranking amps than you do where it's moderate or hot. The battery that originally came with your vehicle was based on averages. At Allied Auto Works, we like to remind Los Altos drivers that they should always get at least as many cold cranking amps as their vehicle manufacturer recommends but may want to upgrade if they live where it gets really cold.
I leave you with my battery joke of the day.
What did the Battery say on his Blind Date?
I have a lot of energy, and I am a pretty positive guy. But I do have a negative side.
DUKE
Allied Auto Works
2073 Grant Road
Los Altos, CA 94024
650.968.7227
https://www.alliedautoworks.com/