How far/long can I drive with a bad alternator but fully charged battery? (3 Viewers)

[thex2]

My alternator died. I'd like to drive my vehicle to the repair shop. Repair shop is 3 miles/15 minutes away. Was just wondering if I could get the vehicle to the shop if I fully charge the battery before or if I should tow it?

Vehicle: 2007 LX 470

 

[trdcorolla]

I would say it depends on how good your battery is. I would turn everything electrical off you can. My wife drove probably 20 miles in her old 2007 V6 Camry with a dead alternator, she didn't know it until she got home. The camry had a deep cycle agm battery, just an fyi.

 

[MongooseGA]

I think 15 minutes should be fine but like the poster above said, it depends on battery. Has the alternator been on its last legs for long? In my experience that can permanently reduce a battery's capacity to hold charge. Ditto on turning every accessory off.

I just had my GF drive mine from home to shop a day or two after it crapped out. I was right in front with jumper cables if need be. No issues. Just don't be an idiot like I was once in high school when I bought a POS Camaro in need of an alt. My buddy and I stopped every hundred yards to charge and jump it. In hindsight, I should have just thrown a good battery in it to get it home.

 

[KLF]

Turn everything off that you can. Should be fine for 15 minutes. I would chance it.

 

[TheForger]

Same thing happened to me, alternator died and I was seeing down to 9.6V on my voltmeter. I turned off everything (A/C, radio, headlights, etc.), and whenever I came to a complete stop at a light I would switch into neutral and try to keep the RPM’s above 1200. I drove 12 miles like this from an Auto Zone to my local shop. Once I got to the shop and turned my truck off, the battery didn’t even have enough juice to crank the engine again (thankfully it wasn’t drained to the point where it damaged it) but at least I made it. You’ll be fine.

 

[FxFormat]

You’ll be fine, most batteries have a 90 min reserve capacity, even if yours is dying it should last you at least 25-30 mins

 

[thex2]

I pulled into my neighborhood last night and heard a loud beep. Saw my battery light on my dash. Immediately turned my headlights off. Beeping stopped and light went off. Drove another 2 minutes to my house or 1 mile with my hazards on since it was pitch black and no headlights. Vehicle starts beeping with battery light on dash again right as I pull into garage. Setup 10amp battery charger to run all night. Hitched a ride to work with my wife today because I didn't know how far I could drive. You guys gave me some confidence I can make it to my mechanic. Thanks for the help.

 

[RKTINC]

I just did 75 miles in my 2008 Avalon. Died 20 yards in front of the dealership!!! Stopped shifting and went into limp mode about 3 miles out.

 

[PabloCruise]

I think the wife drove ours for about a week on a bad alternator, AC/stereo/DRLs, etc.

That was on a healthy AGM battery.

 

[bucfl]

After getting stuck in ruts that someone with 44” tires must have dug. The alt died full of mud. It drove me home an hour away in the rain.

 

[AllLC]

Hey thex2! any chance your alternator is full of mud too? this same thing happened to me a while back. It took 3 batteries to get home (about 30 miles) and when i got home i doused it with several cans of electrical cleaner. Been fine ever since.

 

[AllLC]

the forger: if your battery saw 9.6v you damaged it. you might not need to replace it yet but depending on environmental exposure and usage you might think about replacing it soon.

 

[cwmoser]

This reminds me of my youth in 1966 - I remember because I was in Tech School and my Dad
purchased me a 1964 Buick Skylark that had been burned out firewall forward. I drove that
car for a couple months with just the Battery, no alternator. I simply wired a connection to the Ignition using a piece of wire and and another wire to the Starter. On startup, I opened the Hood, used a Broom Stick to hold the Hood open, twist tie my wire to the Points/Coil, then tapped my wire to the Starter to crank up the motor. Then I would neatly tuck away my wires, close the hood and drive off. No alternator charging and I drove it a couple months until I found an Engine Harness in the Junk Yard and got it properly wired up.
That was a simpler time ... no electronic gadgetry on cars like today.

 

[Live to Ski]

Fun story: friend had a 19 window vw micro bus.cross country road trip from east coast (otherwise known as the "dirty side" in trucker parlance) to, appropriately enough, crested butte. Alternator (generator?) failed outside Denver. He cleverly put several d-size batteries in series to push 12v. Made it to CB...did I say very little available $!

 

[Spike555]

Fun tip for you, race cars do not have alternators. They run an entire race on the battery alone. Alternators take horse power.

Fun fact, you can drive hundreds of miles on the battery alone with no accessories on. The starter takes the most power, then the a/c, then lights, windows, stereo etc.
And obviously the rear defroster takes the most power.

For what you need to do, you're fine leaving everything on and driving to the shop.

 

[fjcruising]

After getting stuck in ruts that someone with 44” tires must have dug. The alt died full of mud. It drove me home an hour away in the rain.

I did the same with an Fj cruise. Charged the battery the next day to get me to the dealer 20 miles out. You should be fine if your battery is relatively new.