I haven’t written much about preparation for emergencies, backups, and things like that in a while. Please allow me a brief excursion in that direction today.
At work today, a young lady requested help with jumping her car. She had a set of cables and a source car available and just wanted help with the process. I applauded her preparedness (silently, of course) until I saw her cables. They were the $9.99 Harbor Freight 10-gauge cables.
I dutifully hooked them up and told her to try it. One very unenthusiastic revolution and lots of clicking. I knew the problem, but rechecked and repositioned the connections a few times with the same result each time.
Another lady who was passing by stopped with interest. I explained that the cables were too thin to transfer enough energy to jump a completely dead battery, which the lady’s was, having left her lights on all day. She went to get her set.
She came back with another copy of the same junk. She started hooking hers up and disconnecting the set belonging to the driver of the disabled vehicle. I stopped her and told her that both sets needed to be connected at the same time. She looked confused but went along.
With both sets connected, it started right up. I disconnected both sets of cables, returned each to its owner, and sent the lady on her way.
All that to say this: Make sure your emergency equipment will actually do the job you’re depending on it to do.
If you blindly trust, you could easily think that you’re prepared, only to find out the hard way that you aren’t.
In this case, cheap jumper cables were worse than no jumper cables. First, they won’t help you, and second, they may cause you to think that the problem is bigger or different than it actually is. The lady today, with the second set of cables, started talking about how the problem must be the alternator since the jump attempt failed. She knew more than today’s average twenty-something female, but not enough to understand how the whole system works.
Most battery cables are 4-gauge, and for good reason. Smaller won’t reliably conduct enough energy to supply the needs of the vehicle, the largest of which is the starter. Since jumper cables have to supply this same amount of current, they should be at least the same size. Thicker if they are very long. You might get one size smaller (6-gauge) to work, but jumper cables smaller than 6-gauge are worthless. You’ll want 2-gauge if they are longer than twelve feet. Google voltage drop over distance and recommend wire size by voltage, current and length. Or just trust that I know what I’m talking about.
The problem is cost. Copper is expensive, and nobody wants to spend $75 for a set of cables when they can buy some from HF for $10 and think you’re prepared.
Grumpy 