Following up on Tel's simple guidance for 2016 models, here's an equally simple solution for everyone else so inclined to disable it.

 

Would it not be better to undo the other end that's attached to the battery? That way you never have to worry about how well you taped it up.

Or just unbolt both ends and be done with

 

Just trying to keep it as simple as possible, and that's easier to get to. I'm assuming people are clever enough to do whatever it takes ensure no metal to metal contact. A zip-tie to another wire somewhere would also ensure that.

I'm all for letting the creativity of others blossom!

 

The second battery essentially goes dead when doing this, right?

 

Yes, that's the battery ground cable for the eco-mode (2nd) battery. The system has no power with it disconnected, so it cannot operate.

The only downside to this is that the 2nd battery will eventually discharge completely, since it is never being charged. Thus, it may need to be replaced for another owner who wants the system, or if the current owner decides to use it again.

 

Is there a control wire that could be disconnected....to allow the 2nd battery to retain its charge? I'd like to disconnect during our summer - the AC keeps restarting the car after only a very short off cycle - it's annoying and not very MPG beneficial. My preference would be to keep the battery charged when ECO is disabled for 4 months or so.

If someone could provide the ECO logic and/or wiring diagram, then I may be able to figure it out - and post it here for others.

TIA.

Desert Hiker

 

In my picture in post #1, you'll see a gray wiring connector on top of the 2nd battery assembly. That has to be what you're talking about.

You could unplug that, assess the effects, and if it generates warning lights, you could always plug it back in.

 

Thanks. Will try and report back, including whether the battery is still charging (elevated voltage) when engine is running.

I would still like to see the 2nd battery/ECO wiring diagram if that exists somewhere.

Desert Hiker

 

It will most likely keep charging because both battery cables are still connected. The two batteries are joined to the charging system inside the battery buss. It will just no longer be communicating with the rest of the car.

 

With the battery disconnected don't you get a warning on the dash when you first start the engine "Stop/Start Not Available" or something like that?

 

One could take the battery out completely and secure the connections so they won't short out. Then, just periodically charge the battery. If/when you want to sell the car, simply re-install the battery. I've gotten into the habit of pushing the button myself. I hit start, eco mode, and loud mode and then go......
It hasn't been an issue for me.
Don

 

I've had my second battery disconnected for a few months now. No dash warning or lights. It will only give the "not available" warning when you press the ECO button.

 

My starting ritual as well...too hard for some here?
I certainly wouldn't go through all the trouble to disconnect the battery...then have to worry if it dies.

 

Too hard for you?

 

I don't put much stock in habit or ritual when I hop in the car, other than letting it warm up before I get on it. Heck, sometimes I don't even fasten my seat belt!

It's an annoyance to many of us to have Eco mode, defeatable or not. Since most of us dislike it, the default position should be "off" and then those few of us who want to use it can turn it on. Eco mode is an example of regulation at its worst, forcing crap on consumers that they don't need or want because it is supposedly "good" for us. A far cry from any legitimate exercise of regulatory power IMHO.

 

You can rail against the fuel economy regulations all you want, but it's a futile exercise. Legislators in both the US and EU could have repealed those mandates at any time over all these years, but they have not. Reducing our dependence upon foreign oil has been popular across the political spectrum. At any rate, democracy has spoken.

A manufacturer doesn't have a choice to make the default option, "eco-mode off," because that's the way it would be tested for fuel economy. I'm surprised they're even allowed to have a button to turn it off.

They can avoid things like eco-mode by building all eco-boxes and no cars like F-Types. If you want cars like the F-Type, then you have no choice but to accept whatever they have to do to meet the CAFE mandates. To me, it's so innocuous, it's laughable to even complain about it, considering the alternatives and reality of the world today.

 

Regulations are passed by agencies, which are part of the executive branch and as such are absolutely not the result of "democracy" in action. They are the result of unchecked bureaucracy. Basically the agency proposes a rule, allows a public comment period and passes it. Nobody is voting for regulations, nor are they voting for the creation of agencies, nor for those who staff them. I am railing about that moreso than the useless and irritating Eco button.

Having said that, sooner or later someone will get killed when the car gets stuck on train tracks in Eco mode and then maybe after congressional hearings this unsafe and useless feature will be relegated to the garbage heap of poor engineering where it belongs.

What I am hoping is that someone will sell me a software patch that fixes the issue, without pulling the second battery or any associated wires. I would readily pay $250'or even $500 for this, just like I had no problem spending money on the smart top module, the spare tire, etc. I love the car. I just want it to behave the way I prefer, not the way some bureaucrats forced JLR to make it. It's got about a dozen of these software issues that I would love to see fixed.

If 1,000 of us buy the modification, it's an easy quarter or even half million bucks for a day or two of programming work. Seems like a decent trade off to me.

 

Nookie, your post is missing numerous irrefutable facts and contains factual errors in the case of CAFE regs. We have 3 branches of government of which the executive branch is only one. As the Constitution stipulates, "they are separate, but equal." Regulations enacted by the executive branch can be repealed or struck down by either the legislative or the judicial branches, and that happens routinely. Regulations can also be enacted by Congressional action.

In this case, the CAFE regulations were originally enacted by the U.S. Congress in 1975 in the wake of the Arab oil embargo. They have been amended by several Congresses over the years. That means they have survived 7 Presidents (4 Republican and 3 Democrat), and 20 Congresses over the last 40 years. They don't tell a manufacturer how to comply with the law, they just require ever tightening economy standards by given dates. Thus, they are clearly not the result of an "unchecked bureaucracy" and are "the result of democracy in action."

The U.S. Congress has multiple ways to fight executive branch regulations. It can either pass a bill repealing a particular regulation, or failing that, a handful of legislators can hold an appropriations bill hostage, effectively defunding certain parts of an agency's operation. Likewise, the courts can rule something "unconstitutional." Generally, it takes years to enact new executive branch regulations because of requirements placed upon the process in laws passed by the Congress.

However, no branch of gov over 40 years has found reason to repeal the CAFE regulations. Thus, as I said before, democracy has "spoken."

 

The stop/start can be permanently disabled via software, but the 2nd battery still needs to be disconnected so I guess that means you wouldn't be interested...

 

The U.S. is a republic, not a democracy. A bunch of usually poorly informed and conflicted politicians have spoken. (though, energy conservation is indeed a noble cause)