Fiction.

As the current flow is warming up the battery plates it's also draining the battery's juice. That's not something you want to do.

I'm sure glad I don't listen to people coming up offering their advice anymore. Usually a few tools end up in their pocket. I sure hope I kept a good eye on him.

I also say fiction,I can't see why diverting some of the batterys finite engery to the lights would increase the amount avialable to the starter.

There is a proven chemical property at work in regards to the battery being able to provide more "cranking power" when the battery is at a higher temp (it probably falls off as the battery gets to hot)

What is your theory (speaking to the OP)to either support or dismiss the question you have asked?

What is your theory (speaking to the OP)to either support or dismiss the question you have asked?

There may be something to it that may make it true but without further expert knowledge I'm still open to the possibility. It could be like tightening a bolt to brake it free before loosening it.

The theory behind this age-old myth is that the chemical reaction that takes place on the battery's plates as it discharges creates enough heat to improve cranking power beyond that lost from the discharge.

Batteries have internal resistance so the more current you pull from them, the more their voltage drops. Turing off the lights reduces the overall current load therefore increases the voltage available to turn the starter. Therefore you should not turn on your lights until the car is running from an electrical perspective.

Everything you've stated is fiction.
WD-40 does not clean carburetors, it does not rot rubber parts, and the cold cranking amps things is really off base.

There are erroneous things posted on this board almsot every single day. Sometimes I argue the point; sometimes I don't.

I tried the WD40 in a dodge 318 with a Holley carb that ran like a Top. One month later I had to replace the carb. he rubber was dried out and snapped like ice.

ok4450 explain your reasons why turning the lights on and off real quick won't give the craning amps a boost.

Question first. Was this Dodge 318 a new vehicle. If not, how old was it? And what rubber are you talking about?
Sorry, I don't buy the WD-40 killing rubber for several reasons, not the least of which is the fact I've used it for decades on rubber with no problem.

When performing a PDI on new cars (Pre-Delivery Inspections) standard operating procedure was to go over all of the door and trunk seals with WD-40. This was done to prevent any squeaks that may occur and head off any complaints from new car owners.
Plug wires, dist. cap, etc. were also sprayed with WD-40 as it is pretty humid here and this was done to prevent the possibility of a new car absorbing moisture in the ignition system thereby causing a no-start or rough running condition.
I've never, ever seen a problem with door seals or ignition wires.

As to the bit about the battery, turning the lights on consumes a few amps of current including the initial surge. The amount consumed is not enough to cause a sluggish or no-start condition or even affect the starter current draw at all.
The starter motor draws a certain load depending on temperature, oil weight, engine condition, etc. and this is not affected one bit by flipping the headlights on.

Matter of fact, the CCA is almost irrelevant if the battery is good because the starter current draw is not anywhere near what the CCA of the battery is.
My opinions are simply based on quite a few decades of automotive electrical work and testing along with what I was taught in a number of service schools.
I had to sit one time and listen to a heavily accented German service instructor (VW) drone on for almost 4 hours about how an automobile battery actually works.
The Gestapo wasn't even that cruel.

Fact On "Exciting" The Battery!

Except, the lights go on and then get turned off, and after a few moments the car is cranked.

CSA, my friend, are you suggesting that it works?

hmmmm, Could be. Come on all you experts. FACT or FICTION?????

Fiction.

tsm, what are your expert creditials that will convience us you are right? Thanks

Expert credientials: former avionics technician, former engineer.
Meaningful credientials: three years living in North Dakota.

But in truth, I'd love to hear the technical input of others on this. I can always be pursuaded by a good proper analytical explanation. I want to hear the "why" behind the opinions.

Amen to that TSM. The "why" as to why it doesn't work and the "why" as to why it works is always nice.

CSA

When you have a headache, do you put a knife under the bed in order to cut the pain in half?

;-))

No personal attacks, you...............you.................you! Besides, it's Holy Days.

By virtue of something being a theory, doesn't even make it an accepted theory, much less proven fact.
Somebody has taken a factoid here, and a factoid there, and there, and joined them in an unholy alliance.
What will give you more cranking power is if you take the battery inside a few hours and let it warm. Then, re-install, and, without delay, start the vehicle.

Wouldn't hurt to charge it while sitting inside too. I do this every two months, only in the winter, on a car I drive short trips twice a week. My last battery in this car lasted over 7 years.