alternator failure: how far can I drive ?

The alternator on my '88 Nissan Stanza Wagon (actually Nissan "Multi", here in Canada) has failed ... and for whatever reason I don't have time to get if replaced before I have to drive about 200 km. (125 miles).

The car is a standard and has no airconditioner. I can drive during the day without lights, radio, fan/heater, etc. It is all highway driving. The batter was recently replaced and it has a new, higher-end, 700 amp battery.

I have been operting lately by charging the battery overnight at home. My instinct tells me that I can probably drive the 125 miles with no problem ... but I would like to get some educated opinons .... Thanks !

-RS-

Reply to
RS
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That must be it's max discharge rate. What you need to know is it's Ah (Ampere Hour) capacity. Divide Ah by load in Amps to find how long it will last. The Ah rated capacity is usually based on 20 hours discharge time, higher rates will reduce the Ah capacity. So if it's rated at 120Ah it can give 6A for 20 hours but will not give 12A for

10 hours and nowhere near 700A for 10min - more like 20 5-10sec goes.

Under 3 hours should be no problem but starting takes a lot out of the battery, try to use a booster battery. If it has an electric fan on the rad try to avoid running conditions that cause it to cut in.

-- Peter Hill Spamtrap reply domain as per NNTP-Posting-Host in header Can of worms - what every fisherman wants. Can of worms - what every PC owner gets!

Reply to
Peter Hill

I am inclined to say "probably." Any chance you can jump-start it? (Or if it's a manual, roll-start it?) That way the only thing the battery is powering is the ignition system and brake lights etc., and it doesn't take that big hit starting the car.

...and like you said, no fan, no lights, no radio - Turn off all other loads.

Cheers, Geoff Glave '88 Hardbody Pickup Vancouver, Canada

Reply to
Geoff Glave

Yes, you'll make it.

Besides, you probably have a few days daylight (no lights, stereo, etc.) running time left anyway, certainly time enough for the couple of hours you'll need to drive 125 miles.

So go for it...make a run for the border.

John D.

Reply to
John D.

I am feeling pretty confident that the battery has more than enough juice to power to ignition system .... however there is the weather report is looking less ideal as I get closer to the driving dates. I gather that if there was heavy rain throughout the journey, that required the windshield wipers ... in such a case, the calculation would go out the window?

I imagine the power draw of the wiper motor might be as much as, or more than the ignition?

Thanks.

-RS-

PS: this car has dual ignition coils. Would it affect ignition, fuel efficiency, etc. if I temporarily disconnected the primary side of one of them ? It's not an airplane, so they are not there *just* for redundancy, I imagine.

Reply to
RS

You're in good company: Eisenhower had the same problem with weather in 1944: He had to decide between going ahead with the D-Day landing or postponing it...again. He went. ;-)

So move your D-Date up to leave or wait...but really, you're only going 125 miles...2.5 hours driving time at most? I think you worry too much.

Besides, IF it rains -- it may not -- just pull over and wait for it to stop...on a hill (if you have a standard transmission) so you can pop-the-clutch to start it rather than let the starter drain juice. If you have an AT and so can't start your car that way, treat your windshiled with Rain-X and you won't have to use the wipers.

Last resort, get a new alternator NOW.

Good luck,

John D.

Reply to
John D.

You will be fine for the trip as long as your battery is fully charged and in good condition. If you are still worried take a spare battery and simply swap out when you finally stop.

Another tip would be to get a battery monitor - several simply plug into the lighter socket. Try to get one with an analogue gauge rather than a Good/Bad LED. As voltage drops exprect problems, ignigtion system will probably still run even when battery is down around 10.5-11v.

FYI -- I ran a Ford Escort Mk II with no altinator for 6 months during a winter in England ! Even running with lights and the cold weather it was still good for a 15 mile comute, sit for 8 hours then a 15 mile ride home.

Reply to
Mark

The trip went well. Only used the radio ... sometimes. Put the battery on charger when I got to my destination. It did not take long for the charging rate of my "6 amp" (never seems to go much above 3 amps though) to drop back to zero ... maybe an hour or so. So I did not need to worry about battery capacity !

-RS-

Reply to
RS

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