Car Battery Selection
Because buying a battery for your car is something all of us will need to do at some point, I thought I’d share some of my geekery as it pertains to car battery selection. My truck will need a new battery soon, and the Mustang will need a battery eventually, so I decided to analyze the options to see what would be the cheapest replacement, depending on how long the next one lasts. I used prices for the BCI Group 58/59 batteries that fit my truck, but price differences between brands for most common sizes should be similar. Results are below, replacement costs assume you replace like-for-like.
- Costco’s Interstate seems to be the clear winner. Not only is it the least expensive initially (by $30), but it’s also the least expensive in the long run, due to the fact that it has the longest free replacement period offered by anyone, as well as the lowest initial cost.
- DieHard batteries are the most expensive to own, at between around 2x-3x the cost of Costco batteries.
- While the Motorcraft batteries have a slightly lower replacement cost than the Costco battery if they fail between 3 1/2 years and 4 1/2 years, when you add the initial purchase price of the Motorcraft into the mix, the Costco battery is still cheaper by almost $30, no matter when it fails.
- Within the NAPA brand, buying the more expensive/longer free-replacement Legend Premium 84 battery isn’t worth it, unless the battery fails between 18 and 24 months (relatively unlikely). The longer warranty doesn’t ever make up for the price increase over the Legend 75.
- If you don’t have access to a Costco store, and you don’t have a Ford, strongly consider NAPA Legend batteries. NAPA stores are everywhere. Their batteries are more likely to be fresh (because of their high sales volume), and while they have a shorter free-replacement period, they beat the initially cheaper Wal-Mart MAXX battery between the 3- and 6-year mark, the time period when a battery is most likely to wear out.
Optima Batteries: I analyzed standard flooded lead-acid batteries, leaving out the Optima and other high-dollar AGM battery options. Why? Two reasons, 1) Because those batteries can cost twice what a flooded battery does, without an increase in warranty (Optimas have a 3-year Free Replacement without any additional pro-ration), and 2) they aren’t as widely available and may need battery tray or hold-down changes to fit. By all accounts the Optima batteries are excellent–they last a long time, they’re leak-proof under most conditions, and they pack more power into the same size case.
However, an Optima needs to last at least 7 years, if not more, to beat front-runner Costco. Not only is that a tall order, but it also assumes that Costco batteries fail immediately after the 42-month warranty expires. If a Costco battery lasts 4-5 years (a reasonable expectation with proper care), then the Optima needs to last at least 8-10 years. Anecdotal evidence suggests that kind of life isn’t unheard of from AGM batteries, but getting 10 years out of a battery likely would necessitate ideal conditions throughout the battery’s life. For the average consumer, especially when used in a daily driver, there are much more affordable options.
Free Replacement vs. Pro-Rated: Receiving a free replacement under warranty does not usually extend the free replacement period; with almost all battery retailers the free-replacement period continues from the date of original purchase. Pro-rated replacements do restart the free-replacement period, but you usually have to buy another battery from the same retailer.
Fresh-ness: Batteries don’t like to sit around doing nothing. They have feelings, you know. Freshness matters. I was at a local auto parts store last week doing some comparison shopping and saw some batteries on the shelf, albeit in less popular sizes, that were a year old. Check the shipping sticker on the side of the battery or learn how to read the manufacturing date codes before you buy. Buying from a store with higher battery sales volumes can help make sure you get a fresh battery.