Battery Question

peace_of_soul

Well-known member
Joined
Jul 17, 2008
Location
Indianapolis, IN
TDI
2000 Jetta, 2012 Passat
Does anyone know if running a battery all the way down and having to jump start it (twice) will ruin an alternator?

Does anyone know how to test for this issue?

Thanks!
 

naturist

Veteran Member
Joined
Apr 2, 2001
Location
Bro Jerry's hometown, Virginia
TDI
2001 Jetta TDI, 2005 Jeep Libby CRD, 2012 BMW X5 35d
Shouldn't, provided it was properly jumped.

take the car to Autozone, Advance Auto, Pep Boys, or any dedicated battery place, and they should be able to test both the battery and the alternator.

But wait, if you ran the battery down twice, did have a dead alternator to start with?
 

JB05

Top Post Dawg
Joined
Oct 20, 2005
Location
Il.USA
TDI
Golf,2005,anthracite blue
A quick test would be to put a volt meter across the battery leads while the engine is running and see if you get at least 14 volts.
Some kind of load test would be the next step as stated above.
 

gforce1108

Top Post Dawg
Joined
Aug 2, 2006
Location
Newburgh, NY
TDI
04 Jetta GLS BEW, 14 Audi A7 V6 TDI
It is very hard on an alternator. They are designed to maintain a charged battery, not charge one from dead.
 

rdkern

Top Post Dawg
Joined
May 21, 2004
Location
Humboldt Co CA
TDI
Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
It seems to me to be likely the alternator was bad to allow the battery to drain twice.
 

Joe_Meehan

Top Post Dawg
Joined
Sep 3, 2005
Location
Ohio USA
TDI
NB TDI, 2002.5, Silver
They are connected. Usually a healthy alternator will survive a battery dying once or twice, but not always. Also a bad alternator can kill a battery. Have both checked before just replacing either.
 

MayorDJQ

Top Post Dawg
Joined
Dec 4, 2001
Location
Williamstown, Mass
TDI
'10 Golf 2dr 6m, sold.
And before replacing the alternator @ $300+ (assuming you don't plan to replace it yourself) replace the $50 voltage regulator.
 
Top