peterk

Just curious as to how long a 96 Jeep will run, at night with the lights on, with no alternator. I had no problem running 85 miles home, 1.5 hours, with the Gen light on and the alternator not putting out anything.

jbsjunk

Depends on how good your battery is.

peterk

A standard issue battery, charged. I went 85 miles in 1.5 hours, but think I could have gone maybe twice as far at night, or about five times as far during daylight. Am I wrong? Any estimates based on experience, battery capacities, the draw from the sparks/computer, lights, etc?

Lowrange2

When my alternator died I winched about another 6 feet and then it died...

Idk, turn your headlights on, leave them on until the battery dies. Subtract a little bit and that's how far you can go.

Engine electronics pull hardly nothing in comparison to headlights and the starter.

Why? Fix the alternator.

MtnHermit

Don't have an answer, but have something for you to consider.

Car batteries are NOT designed for deep discharge. Doing so will quickly kill the battery, been there, done that. Most batteries go for $100+ these days so an expensive experiment.

OTOH, a rebuilt alternator also goes for about $100, so your money, your choice.

salad

No such animal as "standard". There are a lot of variables including climate

Dunno, maybe. Once it gets low enough to kill the engine the battery is likely shot. Complete discharge results in permanent physical damage of these things.

dwright98xj

There is a run time stamped on the battery's label. Usually 95-120 min on average (NEW).

As stated, not recommended, nor is relying an alternator to "charge" a dead battery after it's been jumped. Repeat times doing so = alternator death. It mantains charge, not provide.

Reminds me of telling this woman her serpentine belt was in poor shape and needed replacement. She asks what would happen if it went and she continued to drive. I stated the obvious, well, you'll have no power steering assist, no charge to your battery, and most importantly no coolant flow through the engine. Her response: "oh, but the radio will still work right?" sigh....

5-90

Depends on a number of things - control efficiency, battery reserve capacity, and electrical loading being primary.

If you see your IP voltmeter drop below whatever is nominal for your alternator's output, start shutting things off to extend range...

BimmerJeeper

In my other car, once the alternator light goes on, you have about 30 seconds of driving left.

junkyardjeep

When offroading I noticed my volts dropped cause of alternator dieing. I left as so as that happen and made it 65 miles lights off for about the first 60. Best part is as soon as it died and I pulled over some lady immediately pulls in front asked if I needed a jump. Since my alternator was fried it wouldn't work. But she had a jumper pack and let me drive another 5 miles home with it under my hood.

Boost Happy

That's 20amp reserve capacity. At night you can pretty much cut that time in half.

dwright98xj

Correct. Just speaking general terms.

RTorrez1

Why not just change out the alternator and be done with it???