Quote:
Originally Posted by bennyb53
1. Your number is flawed. From 12.74v to 12.59v is not 15 volts. It is 15 millivolts (15mV). A new battery is 12.6V so at 12.59v is just fine. At 12.74v is slightly overcharged that may indicate a problem with the Alternator's voltage regulator. A failing/or failed alternator will not charge the battery or may even overcharged the battery which is not safe
A load test is done to determine if alternator is working or has failed. It is not done to determine a Parasitic draw. If you have a parasitic draw, it means your battery is being drained over a 2 or 3 day period or if a massive draw the battery is drained overnight.
I suspect your issue is the alternator so you can do the load test. With a volt meter or digital multi meter take a battery voltage reading before starting the car. Start engine and after reaching normal operating temperature turn on your headlights, turn signals radio, fog lights if equipped, a/c or heater and fan on high. Then take battery voltage reading and you should get 14.5 to 14.7 volts. If you get less than 14V you need to replace your alternator.
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yes it's millivolts,. thanks
Again last night, I drove 15 miles, got home, checked the battery, it was 12.88 volts. I pulled the Elect B fuse to stop any drain (DCamps=0). This morning I checked the battery it was 12.64 volts.
You say that's ok. It's normal to drop that much without a load? And is it ok to charge battery that high? I think it hit 12.9 once.
The shop checked my alternator but didn't have me turn on all those things. He said it was a little high, 14.7 or something. I will try your test.
As for parasitic drain, it still shows 0.09 dc amps. I pull "Elect B" fuse now every night to stop drain. I called Nissan and master tech said it should be .05 or lower. I do have a possible clue- the door light always stays on when vehicle is running but all doors are closed, including back hatch that swings up. All some lights are switched off however, so I know there is no dome light drain.