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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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A bad diode in the alternator's internal voltage regulator pack will cause overnight battery drain to zilch.
 

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2011 SRX4 3.0 Engine
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365 Posts
Discussion Starter #23
OK.... 3 tests done......fully charged battery ( with a high tech smart charger) to 100% battery got close to not being able to start the car after about 7 to 10 days

battery starts out after being charged and settling overnight at about 12.8 volts and drops to 12.5..... then decreases slowly about .02 to.04 ( not .2 or .4 ) over a few days , my wife has to drive the car a VERY short distance to and back from work which bumps the charge up about .3 volts then the slow drain continues at about the same pace...

I think the poor thing is not being driven enough ( not her you sickos) 😄 so my plan is to simply put the car on the charger once a week.... don't know what the heck I'm gonna have to do if i leave the car at the airport for 2-3 weeks, maybe rent a car...

any thoughts?
 

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2011 SRX4 3.0 Engine
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Discussion Starter #25
over night, i charged it up to 100% , disconnected the battery and there it was in the morning at a .5 volt difference ....i think its just the battery settling down to a stable state. but i can tell you that simply not locking the doors does cause more drain - even after 1/2 hour asleep. If i feel froggy and pissed off i may do the yanking of fuses route again after jimmying the doors and waiting 1/2 hour for sleep mode. the only problem being that i dont know if a .1 or .05 draw on a circuit is normal...BANG HEAD

steve
 

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2011 CTS4 Coupe, 2014 ELR, 2018 XT5 AWD
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402 Posts
You are saying it measured 12.8 when you took it off of the charger and 12.5 the next morning?
If thats the case the battery wasn't fully charged. 12.5 is only 80%. You can't beleive the smart charger. I have a $600.00 snap on charger and even it doesn't report the correct SOC. I don't think the smart charger got it to 100%
There is only 1 simple way to measure SOC accurately.
1. Charge.
2. Disconnect charger
3. Let battery set with no load minimum of 4 hours.
4. Measure voltage and look up on table.

My suggestion.
Take the car on a nice long drive. Three or four hours. Turn the headlights on. This will raise the system voltage enought to make sure it will fully charge the battery. When you get home disconnect the battery and let it sit overnight. In the morning measure voltage. That should be very close to 100% SOC.
As far as current draw goes the entire vehicle should, after everything goes to sleep, draw less than .020 amps.
 

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2011 SRX4 3.0 Engine
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365 Posts
Discussion Starter #27
Will do :)🚙 i have to see my mom tomorrow a 1-1/2 hour trip one way will note the before and after battery charge from my fluke DMM
 

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2011 SRX4 3.0 Engine
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Discussion Starter #28
just for giggles i went out and measured the battery with my DMM it indicates 12,2 - i hooked up the charger which agreed and indicated a charge of 55%
 

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2016 SRX Premium- Black on Black
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81 Posts
Thanks for providing updates.
Its bad forum etiquette to create a thread asking for help then never providing updates.

Many forum members search the forum looking for already resolved issues and it sucks to find a thread related to an issue you are having but the OP wasn't courteous enough to finish out the thread by posting the resolution to the issue.
 

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2011 SRX4 3.0 Engine
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Discussion Starter #30
Ok an update.... the battery tests over a long period rule out the battery, it should be a minor drain or simply not driving enough ( like only one hour a week ) I have some help in the background on the forum and will post up soon with what i find
 

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2011 SRX4 3.0 Engine
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Discussion Starter #31
Update...So I have determined i do not have a battery drain issue, on the weekend i took several measurements and I am only drawing .008 amps with the car asleep the battery fully charged overnight and disconnected only drops around .02 volts a night. I am going to take the car in anyway for a new receiver module and will have them test the alternator. The SRX is a power hungry pig and it could be that driving it 10 min to work and back is not enough, i will post up what the dealer says .
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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10 minutes is not enough to even get the engine oil anywhere near up to temp. To fully charge a car battery takes quite a while, thus the number of short-hop battery problems, particularly in city/near suburban vehicles. And, partially charged batteries have a very short life.

A fully charged lead-acid battery (12 volt) will read 12.6 volts, disconnected from anything for a half hour. If you can see 12.7 to 12.9 just after charger disconnect that false plate voltage should quickly bleed off to about 12.6.

My STS has a 18 mA parasitic drain - it sits in the garage on a Battery Minder 24/7.

Best bet is the keep the car connected to a 0.8 to 2 Amp Battery Minder overnight. There are types that permanently connect to the + and - battery cables (where - doesn't matter) and the 110V plug hangs out at the grille. Park it, get out, plug in the extension cord.

battery charge table.jpg


........ speaking as a past diesel submarine Main Power Electrician's mate.
 

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2011 CTS4 Coupe, 2014 ELR, 2018 XT5 AWD
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402 Posts
10 minutes is not enough to even get the engine oil anywhere near up to temp. To fully charge a car battery takes quite a while, thus the number of short-hop battery problems, particularly in city/near suburban vehicles. And, partially charged batteries have a very short life.

A fully charged lead-acid battery (12 volt) will read 12.6 volts, disconnected from anything for a half hour. If you can see 12.7 to 12.9 just after charger disconnect that false plate voltage should quickly bleed off to about 12.6.

My STS has a 18 mA parasitic drain - it sits in the garage on a Battery Minder 24/7.

Best bet is the keep the car connected to a 0.8 to 2 Amp Battery Minder overnight. There are types that permanently connect to the + and - battery cables (where - doesn't matter) and the 110V plug hangs out at the grille. Park it, get out, plug in the extension cord.

View attachment 589929

........ speaking as a past diesel submarine Main Power Electrician's mate.
Sub.
If a vehicle is equipped with any type of battery current sensor you should make sure the charging current flows through the sensor.
 

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2012 SRX4 Premium
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304 Posts
Not sure if this is much help, but our SRX usually only gets driven 3 miles a day which is a round trip to work for the wife. No battery issues. It seldom sits more than 2 or 3 days at a time though. When we got her I load tested the battery and it held 1200 cranking amps. With the weather getting colder I should test it again.
 

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2015 SRX Premium FWD
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765 Posts
Ours sits anywhere from 3-4 days to 2 weeks sometimes. I replaced the oem battery a year ago with an AC Delco AGM battery, no problems yet.
 

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2016 SRX Premium- Black on Black
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81 Posts
I agree with what some others have eluded too; I find it hard to believe that the issue that the OP has is related to limited drive time.

My Wife works 3 days a week, 3 miles one-way from home.
Other than those 3 days her SRX generally stays in the garage.

We've never had an issue with the battery draining.
IMO- something is either draining the battery, something is failing in the charging system or the battery is defective.
 
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