Here’s Something That Auto Start-Stop Feature Is Good For

Sometimes automobile accessories have unintended uses.  The Auto Start-Stop feature is one of them.

If you've bought or driven a newer vehicle, you've no doubt encountered the Auto Start-Stop feature; you know - the on-board computer that turns the vehicle's engine off when you come to a full stop (at perhaps a traffic signal) and then re-starts the engine as soon as you pull your foot off the brake to resume driving.  The system is designed to conserve gasoline - by turning off the engine at those traffic stops where you would normally be idling.

Many people find the Auto Start-Stop feature annoying and the internet is full of automobile chat rooms and message boards with questions about whether or not it actually accomplishes what it's supposed to do; or, if it instead puts extra wear and tear on the engine (with the addition of hundreds of thousands of extra starts over the course of the engines life) and the battery.

I recently bought a different vehicle this past summer - my first with the Auto Start-Stop feature.  I don't mind it, actually.  I guess I put my trust in the fact that if the automobile manufacturer has designed the system, it shouldn't put any extra stress on the engine - especially if it's doing what it was intended.  I sort of grew accustomed to seeing it turn on and off when I made my traffic stops.

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For the first few months, the Auto Start-Stop on my vehicle worked like it should. At some point, though - as summer changed to fall - it stopped working all the time - only going through the motion after driving the vehicle long distances.  When I first noticed it, I just assumed that maybe there was more of a draw on the battery and the engine - as the car gradually started calling for more/additional heat as the weather turned colder.  At some point this winter, it stopped working all together; again, I wrote this off because it coincided with a week and a half of sub-zero temperatures.

A few days ago, I brought my vehicle in for servicing.  As part of the oil change and TLC, they tested the battery.  Now - keep in mind - this car is only about three years old, so I thought I had no reason to suspect that it would need a battery quite yet.  As it turns out - that's exactly what the vehicle needed - the stop battery was no longer performing as it was supposed to.  A quick install of a new battery - and I was back on the road again.  And - much to my surprise - my Auto Start-Stop was now back to working aggressively (i.e. operating at every stop - every time).

My hypothesis is that you can use the Auto Start-Stop feature as a 'lie hack' to determine the life of your battery.  If the battery is performing as it should - it will support the on-off cycle of the Auto Start-Stop feature; if the battery is aging - the car's onboard computer will prevent it from kicking in.  A little digging online and my research turns up cooperating evidence to back this up.

So there you have it - a "life hack' involving the Auto Start-Stop feature in your car.  While it's not a scientific test of the life left on your battery, it can give you a pretty good indication as to whether or not you should replace it.