Battery replacement = better gas mileage?

Interesting.I’ve been shopping for performance computer chips on eBay and discovered an aftermarket ground circuit chip from a Japan manufacturer. It appears to enhance and intigrate the grounding circuit while promising to improve gas mileage! Since low voltage computer circuits should always be soddered,resistance might be the issue even in the battery. Maybe continuity can equal better mileage,but then I’m not an electrical engineer.

Sorry…but total bogus…Computers don’t have several states of performance…they either work or they don’t work…If there’s any low voltage that’s low enough to effect the computer…then the computer JUST WON’T WORK…It won’t still be working but not as effective as it use to…It’s either working PERFECTLY or NOT working at all…NOTHING IN-BETWEEN.

Do some manual calculations for the next few fuel stops to see what is happening.

What regal is probably thinking of is the old technique of using a variable (or a set higher) resistance in a part of the engine managment system, a crude way to richen things up

Ok for all you naysayers about batteries not improving things , riddle me this. When I bought my 2010 charger it ran like a top in the coldest winter months, about 3 to four years in , it would run like a really really crappy loud tank on startup in the cold winter months, no amount of research could pinpoint the problem. I resigned myself to the issue , chalking it up to an aging vehicle. 10 years in, I had to change the battery and bam , wouldn’t you know it , no more rough loud idle in winter. My point ? Unless you are an automotive electrical engineer you shouldn’t comment on things you know NOTHING about. A new battery appears to make some kind of differences , how that is I don’t know or pretend to know. My 2010 charger begs to differ with all the naysayers. I suspect not all sensors run off the alternator per se and a crappy battery doesn’t feed those sensors a proper voltage. Again just a guess but with two cars operating better with new batteries I would feel confident saying a new battery improves things that require proper current.

It’s possible a new battery could improve engine performance, but I wouldn’t replace a battery just b/c the engine wasn’t idling well. I’d start with the basic battery/charge system test. Any auto repair shop will be happy to do a basic battery & charge system test for a small fee; sometimes they’ll provide this service gratis.

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Engjneer here… wrong. All 12 volt powered items all run off the same voltage. The battery 12v post is attached to the alternator’s output.

Don’t need an engineering degree to know that. Any experienced auto mechanic knows that, too.


And once again an old thread ( 11 years old ) is revived with nonsence .

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So much for my hopes that this 11 year old zombie thread would quietly die a second death…


Correlation does not necessarily indicate causation.

Whatever was wrong, I’m glad it’s fixed, even if it was accidental.

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agreed , but can you think of anything else that would cause a vehicle to run rough and loud as hell for years to just stop the exact same day the battery was changed ? Did jesus christ come and lay his hands on my car ? lol.

Explain my vehicles miraculous recovery after changing the battery sir.

I did not nor will I attempt to explain any Chrysler product’s behavior nor your perception of its behavior.

I was correcting a couple of misperceptions on your part.


WAG: Depending on how long the battery was disconnected, the TIPM may have experienced a reset, putting things right.


The battery had so much internal resistance that it couldn’t perform its duty of smoothing out and holding the 12V line steady.
Alternator ripple and load changes put noise on the line, somehow playing havoc with engine management, ignition etc.
It’s why with a car with modern electronics it’s a bad idea to disconnect the battery with the engine running.

One little problem with this theory is that the elevated internal resistance would keep the battery from starting the car.

Anyone ever seen a battery with series resistance that disappears under heavy load?

The computer reset theory is more plausible.

Too bad you didn’t put the old battery back in to see if it ran rough again.


The lack of what you consider a better theory doesn’t validate your favorite “confirmation bias” theory.

I don’t have to have a better theory to point out the flaws in yours.

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If you have the car and can’t figure it out, how is a stranger on the Internet supposed to do better?

You’re not being reasonable.

After connecting the battery, the throttle body goes through a calibration process, that is why there was a delay the first time you started the engine. Now the the idle and fast idle speeds have changed.