Preparedness: 2. Jumper Cables

From Fusselman.org

I'd started to work on the "repair kit" section of this series and found myself writing a sub-essay about jumper cables. Jumper cables are one of those things that you should absolutely carry in your car, as they resolve a relatively common problem (dead batteries), and are (almost) the only tool for the job.

Jumper cables are an interesting bit of equipment. Due to the nature of electricity, the longer the cables are (and therefore easier to use, because of car positioning), the less useful they are for actually starting the car, because they transfer current less effectively. The calculations for jumper cables involve a few things: Your vehicle: How easy is the battery to get to? A battery mounted up near the dashboard, or toward the middle of a larger-hooded vehicle will require longer cables. How difficult is your vehicle to start?

Vehicles with larger engines tend to have a larger alternator and therefore make more power for providing jump-starts, though they can sometimes take more energy to start themselves. This is especially true of vehicles with higher compression ratios or those with special considerations, like a Diesel’s glow-plug system, that requires additional power during the start-up process. How dead do you expect your battery to be? If you’re preparing for “oops, my lights got left on” and live in a warmer area, one of those glove box car starters or lighter-cable setups might be fine. If you’re trying to start cars with questionable batteries or other discharge situations, heavier cables are a must. Secondarily, cars get harder to start in the cold. If it gets “really” cold in your locale, go for heavier gauge cables.

For my part, in the middle Midwest, I carry a 10’ pair of 8ga cables. I do find myself in lots of hard-starting situations (not usually my vehicle, anymore), so this makes sense. That said, these cables were purchased a few years back when I had to have a pair “right now”; If I had to do it over, I’d buy a heavier pair of similar length. Even with my full-size Olds, I never had a problem with 10’ not being long enough. Any more just makes them hard to store.

For the record, the author /has/ jumpstarted a car using 8ga car stereo power wire strung between the two vehicles.... This approach is expressly NOT recommended.