ESS on new vehicles

[Carborendum]

WHAT IS ESS?

For those who don't know, virtually all new cars are equipped with an "Engine Start-Stop" system or ESS.  It performs the following function.

• When stopped at a red light, the engine shuts off
• Accessories (incl A/C) will run off an auxiliary battery specifically for that purpose.
• When the gas is pressed again, the engine revs up again.

This tends to save gasoline if you're idling for more than "a few seconds".  More often than not, it will improve MPG in the city by about 1/2 MPG.  And it will have no effect on the highway.

WHY?

Governmental forces are pushing for this technology (not requiring it directly).  That pressure had caused virtually all new cars after 2018 to be equipped with this feature.  I only buy used cars, so I have only recently run into this phenomenon.

UNINTENDED CONSEQUENCES

Within two weeks of purchasing a car with this feature, I found that my batteries were nearly dead.  Research revealed that both batteries tend to last about half as long as the single battery would normally last.  This has to do with the wiring of the batteries and the nature of the charging and ignition systems.  And the batteries required for this system (now on all new cars) are much more expensive.  

So, even though they are more expensive batteries, they wear out faster.  This means we have to pay more often for replacements.

The more expensive batteries use more energy to manufacture (more GH gasses) and they need to be recycled twice as often (twice the GH gasses).

HOPE ON THE HORIZON

I've discovered that there are after-market products that eliminate this issue.  But the installation process seems too complicated for an engine hack like me.  And I have no idea what the side-effects would be.

My mechanic says that they can't replace the batteries.  You have to have a manufacturer certified mechanic do that.  But the certification is so expensive that the mechanic won't jump through those hoops.  So, that means I'll have to replace the batteries myself.

Why can't they just leave things alone?

Edited November 27, 2024 by Carborendum

[NeuroTypical]

How come batteries (plural)?   I don't think I've ever been in a car with more than one battery.  Except for that one time I rode in a Tesla.  But that has no engine to turn off at a red light.

1 hour ago, Carborendum said:

Why can't they just leave things alone?

Government mandates/pressure is absolutely part of the problem, but not that big of a part any more.  Most of it is because people demand technology be added to their cars the second it's been invented.

 

(Full disclosure - selling electronics to the automotive electronic industry probably accounts for a fourth or fifth of my paycheck.)

 

Edited November 27, 2024 by NeuroTypical

[Carborendum]

20 minutes ago, NeuroTypical said:

How come batteries (plural)?   I don't think I've ever been in a car with more than one battery. 

From AI:

Quote

Many engine stop-start vehicles have two batteries, with one being the primary starter battery and the second acting as an auxiliary battery to power electrical systems while the engine is off during stop-start cycles, effectively reducing strain on the main battery; this is especially common in newer cars with a high demand for electrical features. 

Key points about dual batteries in stop-start cars:

Function:

The auxiliary battery provides power for features like infotainment systems, climate control, and other electronics when the engine is stopped during stop-start operation. 

Battery type:

Both batteries are usually designed to handle frequent start-stop cycles, often using AGM (Absorbent Glass Mat) technology. 

Not all stop-start cars have two batteries:

Some manufacturers may use a single high-performance battery to manage stop-start functions without requiring a separate auxiliary battery. 

It's all new to me.  So, I may get some things wrong.  But I don't appear to be wrong on this one.

Edited November 27, 2024 by Carborendum

[Traveler]

@Carborendum :  I only purchase new cars and then drive them until they die.  My current car is 31 years old and could possibly outlive me.  My wife’s car is new and has ESS, but we can control the engine shutoff with the pressure we apply to the brakes when the car is stopped.

Many new cars (my wife’s as well) have lane assist.  I worry more about lane assist because I am a cyclist, and I am concerned that lane assist could cause someone to hit a cyclist or pedestrian.   It could also be a problem if there is debris on the road.  But then lane violations are one of the 3 main causes of accidents (not including minor fender benders) – especially on freeways where it is a main cause (along with speeding).

I am looking forward to the time when vehicles become autonomous.  Though many drivers take responsibility for their driving there are enough that do not.  Driving is a privilege that many mistake for freedom at the peril of everybody else.

 

The Traveler

[JohnsonJones]

I've only used one vehicle (a chrysler at that) which had this in it.  It was my son's van.  It seems you can turn it off if you don't like it.  It had two batteries.  One, I think, is dedicated to the starting and stopping of the engine.  It turned off when you stopped at stop lights, and turned back on when you press the gas.  If a battery has a problem it turns off this process on it's own and acts as a normal car instead. 

I personally didn't really care for it.