What is normal load on alt. with all accessories on?
08-07-2009, 09:19 AM
#1
TECH Fanatic
Thread Starter
iTrader: (1)
Join Date: Aug 2008
Location: Canada
Posts: 1,283
Likes: 0
Received 0 Likes
on
0 Posts
What is normal load on alt. with all accessories on? Just wondering where my batt. guage should be with all my acc on (AC, CD, wipers, rear defrost (this one eats up a lot!), all lights (incl. interior) ) at idle? Normally while driving it sits about at 14 or so, sometimes dipping closer to 13.5 at idle with some accessories on. The batt. reads about 12 or so when car is off so that seems right. Is it normal to drop down to 13ish under full power draw when at idle. I have a new alt., batt., terminals, ignition cylinder/keys, headlight motor etc etc. I am just making sure that I have finally stopped the slow power draw (over a couple days) and that the alt is charging sufficiently. Thanks guys 
*from what I've gathered on here 14'ish is normal under load for these cars it seems correct?
*from what I've gathered on here 14'ish is normal under load for these cars it seems correct?
08-07-2009, 09:30 AM
#2
TECH Addict
Join Date: Jun 2009
Location: Tulsa, OK
Posts: 2,012
Likes: 0
Received 0 Likes
on
0 Posts
Just wondering where my batt. guage should be with all my acc on (AC, CD, wipers, rear defrost (this one eats up a lot!), all lights (incl. interior) ) at idle? Normally while driving it sits about at 14 or so, sometimes dipping closer to 13.5 at idle with some accessories on. The batt. reads about 12 or so when car is off so that seems right. Is it normal to drop down to 13ish under full power draw when at idle. I have a new alt., batt., terminals, ignition cylinder/keys, headlight motor etc etc. I am just making sure that I have finally stopped the slow power draw (over a couple days) and that the alt is charging sufficiently. Thanks guys
*from what I've gathered on here 14'ish is normal under load for these cars it seems correct?
*from what I've gathered on here 14'ish is normal under load for these cars it seems correct?
08-07-2009, 01:33 PM
#3
TECH Fanatic
Thread Starter
iTrader: (1)
Join Date: Aug 2008
Location: Canada
Posts: 1,283
Likes: 0
Received 0 Likes
on
0 Posts
Yes, what you're seeing is normal. Alternators don't go to full output until engine speed is above idle. If you have everything possible turned on, it's quite possible to be operating your electrical system in a deficit which will slowly cause your battery to go dead if left at idle. The only way to know for sure if you're in that situation is to measure the total current draw of all accessories and then measure current output of the alternator at idle using a clamp on ammeter. Current is the key, not voltage.
Thanks man. 