Car repair question

[philo]

Recently replaced the five year old battery in my car and that solved the problem. Battery was weak and after sitting for 24 hours, the voltage dropped to 12.0 volts and car would not start.

Back in the old days, if one had a weak battery, the engine would turn over a few times, then totally stop.

This one stumped me at first because the engine turned over pretty well but would not start. Battery warning light went on...and it started immediately with a jump.

Just curious as to what a low battery would prevent from working. Ignition voltage? Fuel pump? what ?

[invalid unparseable]

Cars today are full of electronics and batteries do not last as long.

My first google hit on the question:

[philo]

Seems to be a logical answer. I just did not suspect the battery at first because the car did crank.

[philo]

The thing is, once the car starts, the alternator can supply all the current necessary. At any rate, the battery was five years old...which has been pretty much the norm for me within the past 30 years.

[Thomas]

If the battery is totally dead the alternator cannot keep the car running. Old school, ok.

[micky]

Is that new? What about the advertisement in the 60's when they started the car, took out the battery, and drove to the opposite ocean without having a battery. Is something different about cars today? If so, that's what the OP Philo was asking about. What's differrent?

BTW, welcome back Philo. Did you have a longing for OT politics?

[Clare Snyder]

The computer needs minimum 9 1/2 or 10 volts to fire the ignition and injection. The gear reduction starters only need about 75 amps to crank the engine - but a week battery can drop below the required voltage and STILL spin the reduction starter

[Clare Snyder]

I've been averaging better than 7 years but I fon't buy cheep batteries - cold winters and hot summers here between the lakes in CentralOntario

[Clare Snyder]

Generators could do that. SOME alternators can - but many can not. Alternators require power to make the field magnet

[philo]

I know I have driven cars with the battery disconnected, the alternator supplies the current.

I have been fortunate in that I have not had too many home problems that required me to need help...but I figured the car question was close enough>

I have stayed off Usenet

1) Because I don't want to get in political discussions 2) I now live part time in Colombia and don't bring a computer with me and the news server I use on my phone does not pickup this group

[philo]

Years ago, I found out the hard way...not to cheap out on batteries.

[philo]

I am quite sure the battery must have dropped well below ten volts.

I have to get use to the new technology

[micky]

This first excuse is not surprising, but the second one is very imaginative. Speaking as your commanding officer, if you dont' get back here full time, you'll be charged with being AWOL and sentenced to the usenet-brig.

[micky]

It took me a while to remember all this: I defintely remember being told when alternators came out that they had higher output** at low RPM than generators do, and that was enough to keep the car running at idle. And they definitely said or gave the iimpression that generators couldn't do this, that the generator output was so low at idle speeds without a battery to see one through those periods, the car would stop.

And this was confirmed because when I had a car with a generator, the battery light would go on or the ammeter would show slight discharging at idle. Cars with alternators that I had later I don't remember any having an ammeter but I put one into one, a '73 Buick Centurion, and it never showed discharging when the car was running.

**Why that should be, they didn't say. Seems that the output should be higher at all speeds, or lower, or the same, at all speeds

[philo]

Terrible wife , forcing me to go to a place with no winter !!!

[philo]

Funniest one I did was put the battery in backwards in my '53 Chevy 3100

The generator just re-polarized and all worked fine.

Only reason I knew was the gauges read backwards.

The radio was the vibrator type so it did not care.

[invalid unparseable]

I too am learning with all the new technology in cars with computers, chips and sensors. A few years ago I gave my dwell/tach meter and timing light to Goodwill as they are no longer used.

A couple of years ago with new car a guy in the park asked me for a jump and I turned him down hearing that if done wrong you could fry your cars computer and be in a world of hurt.

A couple of weeks ago my BIL changed the battery in his car and went in for inspection and failed. Apparently with new battery it might take a day or so for computer to reset to normal and it may have been throwing bad codes. Today inspectors do not sniff your exhaust with machine but plug into cars computer to read sensors.

[rbowman]

It's a new world. I went out one day and the DR650 wouldn't start. This is a oil-cooled single cylinder engine with a carburetor that's as sophisticated as a lawn mower but it does have a ECU module that died. No work around other than replacement.

[Leonard Blaisdell]

Yup. A couple of years ago, I changed the battery in my 2013 Tacoma and drove it in for inspection. Fail. I drove it seventy miles on the highway and brought it back. Fail. I drove it around the "Ring Road" (about 23 miles with stop and go). Fail. I puttered around town for about twenty miles. Pass. I didn't realize that it was a big production.

Some things were better in the olden days.

[philo]

Now that the car has a new battery in it, I decided to check for abnormal current drain.

Yep...there is a 900 milli-amp drain. 50 Ma would be more normal.

Checked to make sure no lights are on such as trunk and glove box. Cannot find anything, so I am going to take it in to my regular car shop. I have been going there for 50 years so I can trust them. My first repair with them was $7.50 I think this one will be a bit more.

At least I found out one thing I was curious about. There is a little grip inside the trunk so one could get out if one were locked in.

The grip is glow in the dark.

LOL