New battery - why does all work so well?
 

Battery died. Bought new battery with a bunch of CCA @ zero F - 730.

Why does everything work so damned well when running with the new battery vs the tired battery with the alternator cranking out 14-ish volts?

When I pulled it out of the driveway I was setting trees on fire with my low beams. Stone cold and good throttle response and it's 15 degrees F outside.

Does the car draw from the battery only and not the alternator?

No, but maybe when you got it replaced they spruced up your ground or B+ terminals and removed corrosion etc? Which may have led to your previous battery's demise?

Who cares, enjoy setting the trees on fire and that your new purchase is paying dividends beyond its intended purpose. :D

Cause anything "voltage-related-levels-affected" could/will operate better.....would be nice if you had some various voltage measurement points before and after?

Along the same line, I've experienced the same "improvement" after changing out the DME relay! Completed convinced of my butt dyno,...knowing it to be true. Then the engineer sets off to determine "why" this is........fuel pump voltage levels? System levels? Instrumentation levels? On and on,...never measuring anything, per se'....but feeling the car be "stronger" in what it does.....

I'm a FAN of "good" DC levels!!!!!!!!!!!!!!

Which battery did you install?

BEST!

Doyle




Doyle

There's volts and then there's amps. Therein lies your answer.

I installed the Sam's Club Duracell model 48. It was one of two flooded lead/acid batteries offered for cars. The other was the 60 lb beast for the 930. All the rest were non-maintenance sealed units.

The link says it is a non-maintenance battery but it has ports for each cell and vent holes so , maybe I am missing something.

Duracell® Automotive Battery - Group Size 48 - Sam's Club

My pal has an RV and I did a couple hours of research on his deep cycle house batteries and many peeps state the fancy deep cycle batteries (e.g., AGM) last no longer than a well tended open cell type battery. So I chose the chubbier 48 model than the standard 47 model. More for an experiment of life duration than the need for 150 extra CCA.

No I have to figure out where to drain the vent ports. :-)

I think I got them both!!!!

,..not forgetting the "resistance"............aside, "source voltage health" is a good thing,....it will provide you the amps (assuming you've no "resistive" issues).

As TAG noted, grounds are serious culprits and MUST be HIGHLY conductive to give ANYTHING a chance....

BEST!

Doyle

Your battery is not only closer to the headlights, lower ohmage path, but the alternator is putting out ~14 volt PULSES of DC. So yes, the battery will be the primary voltage source for the headlamps, etc, since it is used to "fill in" the voltage "valley's between each alternator output "pulse".

The poorer the battery be the deeper those voltage valley's will be so the average voltage will be higher with a NEW battery.

Take an O'scope reading all the way back there in the engine compartment where the alternator resides vs one across the battery, new vs old, to get an idea.

A major cause of battery failure can be attributed to the accumulation of metallic debris flaking off the cell plates and settling in the bottom of the battery case. Enough debris and a cell or two gets shorted out at the bottom. Deep Cycle batteries typically have deeper case area beneath the cell plates.

I am with you and appreciate this. I went kinda "anal" installing my MSD box (and associated [primary] grounds) based on talking to Steve Weiner a few years back.

I did work the connections at the new battery vigorously so maybe that helped?

I touched nothing other than the battery connections during this project so.......

FWIW - The old battery would not start the car without a jump.

To answer your multiple questions. An old battery looses volts and amps. You can probably start the car with 11 volts. Headlights and all electrical things will not be at full power. The new battery is probably making 14 volts, and 200 or so amps. Second, the car runs off of the battery! The alternator charges the battery. A car will run without an alternator until the battery dies, but it will not run with a dead battery, even if the alternator is working. Ask me how I know. You may have had a bad connection to ground with the old battery, but not necessarily so. If you have not done so, go to your flaps and get some grease for your battery terminals. Remove the connections and grease them good and reinstall. This will prevent corrosion from developing and giving you a bad connection.

Battery was sub 12 V and needed to be started with a jump from another car and would not hold a charge. Everything was whimpy. Drove it around the block and when you would shift gear,s the drop in RPM's would dim the lights.

As to the car running off the battery vs the alternator, I would like to think this is true given it answers the basis for the symptoms. However, I did not take voltage readings at other than the battery terminals (old battery) when being charged.

That is not an absolute, and certainly not true in this case. Although newer cars are designed to run with the battery in place, an old clunker from the 70's and 80's will start solely with jumper cables and run. I won't run great, but it DOES run.

Agree with Tag on this one,...it's a twin deal here.

Battery gotta' be "there"......too!!!!!!!!! (In the end). that alt will max.....I bet?

BEST!

Doyle

Has to be on full tilt.

On a side note, my passenger window that has been suspect as far as up and down speed, was pretty much static in the 15 degree temperature (with new battery). Driver's side was the speed of light. Lends support to the grease the track threads.

Really old cars used magnetos. Only needed a spark to run. No battery and no charging system. Then Generators were developed. Engine would run without a battery. Generator made the electricity. Today a car runs off of the battery and the alternator's only job is to charge the battery.

Yep, back in the late 80s, we had a bunch of those cars in the shop for training purposes. From time to time, we had to move them around and we had a single battery for five or six cars. We just started up one and moved the battery to the next car. Once they were running, they could be driven about.

That is cool. I disconnected the battery the other during an ADD moment and it kept running. Is there a downside to this?

Yes,..there is,...many threads on this, Bob.

Best!

Doyle

That is cool. I disconnected the battery the other during an ADD moment and it kept running. Is there a downside to this?

Modern (cars with alternators) charging systems need the battery in place while running. If you disconnect the battery..the alternator will go full output (trying to charge the open circuit spikes to above 13v/14v (your alternator is now trying to charge the whole world) The voltage spikes can damage your ecu and other items.

This won't be healthy for long..the alternator will burn out too.