Alternator belt breaks...car will go how far on battery?

[SPIKER]

I had my alt die on my old cougar. I drove it for about 2 weeks while I had the alt apart rebuilding it and polishing it to a nice shine (polished aluminum still looks good) I started & stopped it probably 20+ times, and even ran lights & radio as needed. it is a 74 with next to 0 electronics breaker-less ignition though... new cars as mentioned are lucky to go a few miles with serpentine belt, my 91 f150 overheated after water pump froze up & tossed belt. was all of 1/4 mile after lights indicated it froze up (and a lot of nasty noise too lol... lucky I was only 1/4 mile from home and on way home.

mark m

 

[Soundguy]

That's funny, that's exactly where we are on an old International 444. Instead of replacing the battery though, we just do a recharge every now & then when it starts turning over slower.

Must be something about great minds thinking alike....

when i got my ford 5000 diesel tractor, the genny on it didn't work. That tractor uses a real hefty long 12v battery.. the prev owner would just charge it up once a month... The only power it used was on starts, and the oil lamp that came on at startup. The bat lamp -WOULD- have been running to show discharge.. but he pulled that one out

Soundguy

 

[techman]

With headlights on you might get 2-3 hours, without around 6.

Keep air, heater, RW defrost and other big electrical power hogs off if it happens.

paul

 

[VA_Joe]

Not very far in a modern vehicle, especially if it happened at night when you needed your lights on. Older vehicles without much in the way of electronics could go for quite a while. The computers are fairly sensitive to voltage and that is what's most likely to shut the vehicle down even if the battery still has some juice in it. Not to mention (I know you said exclude it) the darned serpentine belts that also run the waterpump. At least this is what we found when the alternator went out on a friend's Cavalier (fuel injected).

That's the problem. Once the voltage drops below the batteries nominal level, the car shuts down. In the old days you could go a long way (even further with the lights off).

 

[schmism]

If you have a healthy battery and your 4 or 6 or 8 cylinder car is in general good upkeep and you blow a alternator belt (forget the reality that many belts today power other items)... how far might an 'average' car travel on battery before it dies?

my wifes 325is alternator died on the way home (light on the dash came on) aobut 10 miles into a 50 mile commute. Not knowing what was wrong she continued home. The radio quite about 15 more miles in and she made it another 18 or so miles before the car died and she coasted to a stop on the side of an exit ramp, in downtown STL rush hr traffic. A motorest assist found her within about 2 min (she was within sight of a traffic monitoring camera were they dispatched the guy) he hooked up his extra long jumper cables and kept both connected for the ~15 min it took me to get the rescue call and come get her.

we disconnected the cables and i emidatly headed for the nearest exit. We parked it and went to dinner waiting for traffic to clear incase we had to flat tow the last 5 miles home.

after dinner i made it home with no radio or lights. but it would not start the next morning.

while it wasnt a broken belt, and perhaps the alternator was putting out a few volts, it wasnt enough to keep the car running.

in short, a 94 bmw will make it ~40 miles on the interstate.

 

[Soundguy]

Stuff like this makes owning one of those booster packs extra nice.

I have one that has an air pump, lamp, and cig lighter adapter onit. Comes with a lighter to lighter plug.. that might make the difference in a few miles walk.. or getting home.

Pretty decent unit.. think I paid 40 or 60$ for it. I had a flat batter on my 70hp diesel tractor the other day.. would turn over but not enough to take off. I was skeptical that this pack would help.. but I put it on, and turned it on for about 5 minutes, and then hit the key... While it wasn't like a fresh battery or anything.. it did kick it enough to take off and go. ( meter ont he unit said it was 50% discharged after that.. I was quite impressed... )

Soundguy

 

[VA_Joe]

Stuff like this makes owning one of those booster packs extra nice.

I have one that has an air pump, lamp, and cig lighter adapter onit. Comes with a lighter to lighter plug.. that might make the difference in a few miles walk.. or getting home.

Pretty decent unit.. think I paid 40 or 60$ for it. I had a flat batter on my 70hp diesel tractor the other day.. would turn over but not enough to take off. I was skeptical that this pack would help.. but I put it on, and turned it on for about 5 minutes, and then hit the key... While it wasn't like a fresh battery or anything.. it did kick it enough to take off and go. ( meter ont he unit said it was 50% discharged after that.. I was quite impressed... )

Soundguy

BTW - tried this once with a bad alternator - doesn't work too well. Not enough voltage to keep the electronics running for long (nominal output voltage of the alternator is 13.6 volts vs. 12 volts for the battery). Once the battery drops below its nominal 12 volts - the electronics start shutting down. They way I got the car home that day was to get jumps every 5 miles or so to temporarily bring the battery back up to charge.

Joe

 

[Soundguy]

Some of those booster packs are different. many use a slightly higher voltage output to actually charge your car battery a bit.

I agree.. if you only have 12v available on the pack.. you are just lending it's AH capacity to the unit already installed. once the hungry electronics draw it all down.. you are looking for a charge..

soundguy