so i let a friend "borrow" my alternator because they were stranded. can i drive my legacy 20 miles home without the alternator, on just the fairly new Optima battery?

I drove nearly 30 in daylight when my own alternator was bad, to get the new one! I practiced shorter trips in my neighborhood before venturing 15 miles one way. Of course, the battery was fully charged off-line in my case.

Maybe, because the optima is a deep cycle battery (i think) you could probably make it as long as you didn't tax the electrical system too much i.e. not to many stops and starts. If it's mostly highway then I'd give it a go. Would suck to get stranded though...

Yes:) ...... I agree with 94legwag ,but as long as do not need to wait to long at traffic lights . Brake lights will eat some power.

94legwag is right those batteries have a very high CCA , so you should have no real issues. Charge battery when you get home, and good luck

Edited August 21, 200916 yr by imprezaII
missed something

You actually may or may not, depends on a few factors, its not strictly how many amps you are drawing or how many miles your going to drive. You can have a battery that has built up sulfates on the lead plates and hold much less charge than a newer battery or a low specific gravity count. More sulfate buildup reduces the overall quality of the battery and battery cycles.

 

On two separate occasions in the past I was able to drive 19 miles and the other occasion the car lost power 1/3 the way there and died out. Both times were on fully charged batteries.

 

Some related main factors:

1. How much specific gravity you have (electrolyte). Most 12vdv automotive batteries should have a specific gravity of 1.26.

2. How old the battery is.

I personally wouldn't drive 20m on a battery older than 1 year. This is because

I have used many batteries that last roughly 2 years. Several had warranty replacements & had to be returned to the store within 2 weeks. New car batteries seem to last 5 years for me on average. The Optima batteries are this grade but big $$. Marine grade batteries are more reliable and as long as they are regularly re-charged they will last at least though the warranty period. A load tester can also help determine how well a battery can handle the load.

3. Battery cycling- batteries need to be regularly cycled.

4. Weather-cold weather is hard on batteries. (this obviously isn't a factor

this time of year).

5. How many starter crank amps you consume.

6. How much load your carrying in the car.

7. How many hills you will be driving. (1 HP=746 watts= 1HP=33,000 ft lbs of torque or 550 ft-lbs/sec).

 

These are some factors relating to your answer but not all. Someone may list how many miles they have gone but it doesn't mean all the factors will match yours.

Best of luck either way and get back to let us know how it all worked out.

Few years ago I was 100 miles from the house and lost the battery because the alternator failed. Wife came to rescue me with jumper cables. I jumped off her battery for about 20" and drove home with no problem.

 

Edit: Doesn't the belt that drives the alternator also power other things like the water pump?

Edited August 22, 200916 yr by john in KY

"borrow" an altenator?!?!

 

 

Like 98sub said, you might be OK you might not. There are a lot of factors involved that could determine whether you make it or not.

 

When I was about 12 I was on a trip with my family and about 60 miles from home (we had just left) the alternator in our van went kaput. It was night, and we made the 60 mile trip back to the house without any trouble. The headlights were kinda brown but still on and everything was functional.

Fast forward ten years, I'm leaving for work one morning in my 97 STS. Get about a mile from my house and all the warning lights in the dash pop on, voltage meter is dropping quick, and as I pull into the lot at work, exactly 3 miles from my house to my job btw, the car quit. Battery was only 6 months old.

I drove my truck at work (a freightliner with the headlights on and all the lights on a set of doubles) like 15-20 miles on the freeway with the alternator belt missing. (drove it to the shop rather than wait for a service truck)

 

Made it just fine... then again I have 4 HUGE batteries

I bet you'd be fine as well considering you've got a good brand of battery. I've got a story too, I lost the alt in a chevy starcraft van and didn't realize it. Drove it around town for three days before the battery finally quit. Not lots of mileage, but lots of starter action.

 

You're probably thinking that you don't want to buy an alt 'cause you have a box full of them at home, how about someone brings you one?

 

Good luck!

 

Will-

i made it no problem.

 

apparently folks have been dying to talk about battery technicalities, wow!

 

yes, i let someone "borrow" my alternator, i have extras at home. otherwise they would have been stranded and had to leave the car. i was thinking about getting a new one anyway, i drive a lot so having an old unknown alt isn't that appealing.

 

Edit: Doesn't the belt that drives the alternator also power other things like the water pump?

not on EJ engines, water pump is timing belt driven.

The alt belt does power the power steering though.

I've done it a couple of times when my alternator was going out, 35 miles each time. So if you have a good battery turn off the radio and fans and head home.

I've done it a couple of times when my alternator was going out, 35 miles each time. So if you have a good battery turn off the radio and fans and head home.

 

Yeah turn off all unneeded accessories, when you get to a stop light switch to N and step off the lights, don't use headlights until you have too...etc.

 

That way you can maximise your battery.

The alt belt does power the power steering though.

 

But GG is strong like OX so i bet he didn't even notice it.

But GG is strong like OX so i bet he didn't even notice it.

i was really confused until i saw the ":lol:"

 

that dinky 1.8 liter behind an autotransmission means i'm going so slow i have plenty of time to work with!