Battery Replacement

Today's topic is batteries. It seems like everything in St. Louis Park runs on batteries. Of course, the batteries we’re most concerned with here at Edina Tire & Auto are those in our vehicles. Car batteries wear out just like any other battery and need to be replaced. There are a couple of things St. Louis Park drivers should know when looking for a new battery.

There are two measurements that come into play: one is cold cranking amps and the other is reserve capacity.

Let’s start with cold cranking amps. This can be thought of as the power output used to start a cold engine. The number of cold cranking amps you need depends on your vehicle and where you live, specifically how cold it is where you live. The two factors are that the colder your minivan'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 in the cold. We even have a table. Let’s say it’s eighty degrees Fahrenheit out. 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 eighty degrees.

As you can see from the chart, the colder it gets, more power’s needed, but the available power drops.

Percent of Power Available	Celsius	Fahrenheit	Power Required
100	27	80	100
65	0	32	155
40	-22	0	210
25	-32	20	350

So if you live where it’s cold, you need a battery with more cold cranking amps than you do where it's moderate or hot. The battery that originally came with the vehicle was based on averages. At Edina Tire & Auto, we like to remind St. Louis Park auto owners that they should always get at least as many cold cranking amps as the manufacturer recommends, but may want to upgrade if they live where it gets real cold.

And the type of engine you have will impact the battery you need: A six-cylinder engine requires more cold cranking amps than a four. An eight cylinder needs even more. And diesel minivans require more than a gasoline engine with the same number of cylinders.

Now on to reserve capacity: It’s a measurement of the number of minutes of reserve power the battery has at a given load. The number is more important to St. Louis Park drivers these days because of parasitic drain. Parasitic drain is the battery energy that’s used when the key is off in your minivan. So, the power drawn by the security system, the remote start system, even the power the computers require to maintain their memory.

Reserves are also needed when you make very short trips around St. Louis Park. You’re not driving long enough for the battery to recover the energy it used to start the engine. So go with the minimum recommended by your manufacturer or Edina Tire & Auto and upgrade if you need more.

Talk with us at Edina Tire & Auto about your options. If you need more from your battery, a larger, heavy-duty battery may be called for. At Edina Tire & Auto, we remind our customers that it’s very important that the new battery fits your minivan: the terminals can’t be touching other parts and stuff.

Batteries are a big ticket item for most St. Louis Park motorists, so the warranty gives piece of mind. There’re two kinds of car battery warranties: pro-rated and free replacement. With the pro-rated, you get a credit for a portion of the battery if it fails during the warranty period. With a free replacement warranty, you get just that, a free replacement. Be sure to ask us at Edina Tire & Auto about the warranty so you know what you’re getting.