Battery draw 2015 Genesis when sitting

[Solidjack]

Hello everyone,

I have a 2015 Genesis 3.8 with around 70k miles on it. Since we bought it used at around 50k miles last year it’s had an issue where leaving the car sit for over 2 days results in a stone dead battery. It has had 3 new batteries installed in the last 12 months and spent over 20 days at the dealer where they tried to figure it out to no avail.

I have a background in engineering with some electrical but I don’t have any of the tools necessary to interface with the genesis onboard and the dealer has no idea where to go from here.

I have been messing around with some testing and pulling the fuse for the main center stack fixes the issue. This is basically what we do when car sits at airport etc.

I do really like this car but does anyone have any suggestions on where to go from here for testing or had a similar problem. Pulling fuses doesn’t feel like an ideal approach to finding electrical gremlins in a car this complex

 

[arcman]

If you don't already own one, get a multimeter and check the voltage drop across the fuses. Lot's of videos on how to do this on Youtube. Here's one that shows where to go to get the charts for different size types of fuses.

You should be able to narrow down where your high current draw is located using this method in a matter of minutes.

Also, get yourself a battery tender style charger if the car is going to sit for a more than a few days at a time when not being driven. I picked up one from Amazon made by Schumacher for $15.

 

[silberma]

As an engineer I can tell you that in order to have a voltage drop it has to be measured across a resistance. With the fuse in place you can't measure anything because there is no resistance in a fuse and therefore no voltage drop. You need to remove the fuse and measure for current flow across the terminals. Correct me if I am wrong.

 

[arcman]

Dang... My first post and someone tries to bust my balls. Tough crowd here.

Not being an engineer, I'm relying on the many videos posted on Youtube about voltage drop across fuses. No one went to the trouble to make those charts because it's some kind of black magic.

The fuse has to have some kind of resistance, whether in milli-ohms or micro-ohms (I don't have a clue) that creates the drop.

 

[Solidjack]

Hey all thanks for the ideas. Trouble I ran into with trying to check draw is when you open the door so many things turn on so every test I basically had to setup, shut the doors etc and let everything go to sleep then check periodically for latent draw. Car has been at dealer for around 40 days this last year and they still have no idea what’s going on. I realize it’s higher mileage (about 70k)but I didn’t expect this long of a problem or for them to have no tools to find this type of issue. It runs the battery dead consistently within 30-40 hours so I assumed this go around they would be able to find something but seems like they are getting nowhere. They said they called Hyundai to no avail. Feels like it would be easier to wire it like a land cruiser and just install a second battery at this point to deal with starting so I don’t have to jump it 3 times a week.


I can do a battery tender etc but that is frankly as much work as just jumping the stupid thing, unless I get fancy and wire one in so I just have to plug it in like a block heater.

Again, thanks all for the ideas. I’ll see what I can figure out if I ever see the car again. Driving this Nissan note isn’t quite the same

 

[silberma]

Dang... My first post and someone tries to bust my balls. Tough crowd here.

Not being an engineer, I'm relying on the many videos posted on Youtube about voltage drop across fuses. No one went to the trouble to make those charts because it's some kind of black magic.

The fuse has to have some kind of resistance, whether in milli-ohms or micro-ohms (I don't have a clue) that creates the drop.

-----------------------------
The wire in the fuse is a very good conductor of electricity and you will not be able to measure a voltage drop. This wire differs from a copper wire in that when heated it will melt and cause an open circuit. A copper wire will just get hot and burn the insulation

 

[pmckechnie]

I'm sorry, but only a super conductor has 0 ohm resistance. There are no super conductors in cars. The heat that melts the fuse comes from the current flow through the resistance.
I do not believe that measuring the voltage drop across a fuse is a valid diagnostic test. There are a lot of other factors that come into play. Temperature for instance. A cold fuse will have a lower resistance than a hot fuse.
I worked on cars with problems of the battery going dead over time for many years. It can be one of the hardest problems you can have on a newer car. It took me many years to learn how to do it. Every problem was different. You have to have complete wiring diagrams, Accurate equipment, and years of experience.
One thing you could try is go out at night (dark) after the car has set for at least an hour so all the computers/control units have gone to sleep. Leave the key fob inside away from the car. Without touching the car, look for things like light coming from around the glove box. Lights in the trunk (have the door open at the back seat to the trunk). Look around the hood. Look at the dash. Welcome lights, etc. These are just examples. The security light flashing is the only thing you should see and it is OK.

 

[PaFromFL]

(As a physicist,) the reason a fuse works is that is has enough resistance (R) that the I^2R power is enough to melt the fuse at the specified current (I). A 20 A fuse probably has a resistance of a few milliohms so that a 1 A parasitic current would produce a voltage drop of a few millivolts (note that resistance increases if the fuse gets hot). A good voltmeter could detect this. If the parasitic current were 100 mA, the voltage drop would be a few hundred microvolts which is much harder to measure.

The best way to measure the parasitic current would be to insert an ammeter in series with the circuit in a manner that will not disrupt the flow of current (because digital circuits can drastically change current draw if a power reset occurs). For example, the ammeter would be connected between the battery clamp and battery post before the clamp is disconnected from the battery. This continuously provides current flow, first directly through the clamp, and then through the ammeter. For a fuse, the ammeter would connect to each side of the fuse holder before the fuse is lifted (not easy with modern fuses and fuse blocks). Be careful not to destroy your ammeter by accidentally connecting it across ground and 12V.

 

[AcerOne]

Just an obvious question that may have been answered but do you have a cell phone charger or any form of charger plugged in? They draw power even with no phone attached and is a common culprit for battery drains on vehicles.

 

[Suburbazine]

Just an obvious question that may have been answered but do you have a cell phone charger or any form of charger plugged in? They draw power even with no phone attached and is a common culprit for battery drains on vehicles.

Shouldn't matter, convenience circuit cuts power to all the outlets when the car is turned off.

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[Rittam]

Hello everyone,

I have a 2015 Genesis 3.8 with around 70k miles on it. Since we bought it used at around 50k miles last year it’s had an issue where leaving the car sit for over 2 days results in a stone dead battery. It has had 3 new batteries installed in the last 12 months and spent over 20 days at the dealer where they tried to figure it out to no avail.

I have a background in engineering with some electrical but I don’t have any of the tools necessary to interface with the genesis onboard and the dealer has no idea where to go from here.

I have been messing around with some testing and pulling the fuse for the main center stack fixes the issue. This is basically what we do when car sits at airport etc.

I do really like this car but does anyone have any suggestions on where to go from here for testing or had a similar problem. Pulling fuses doesn’t feel like an ideal approach to finding electrical gremlins in a car this complex

I had someone make the same suggestion about the fuse, but why should the owner of a 2015 Genesis have to be digging around in the fuel box?

 

[Rittam]

I had someone make the same suggestion about the fuse, but why should the owner of a 2015 Genesis have to be digging around in the fuse box?

 

[EdP]

I had someone make the same suggestion about the fuse, but why should the owner of a 2015 Genesis have to be digging around in the fuse box?

Obviously you should not have to. It is a good idea to save the battery though, until it is figured out. Takes a good tech to find problems like that though.

 

[Rittam]

Hello everyone,

I have a 2015 Genesis 3.8 with around 70k miles on it. Since we bought it used at around 50k miles last year it’s had an issue where leaving the car sit for over 2 days results in a stone dead battery. It has had 3 new batteries installed in the last 12 months and spent over 20 days at the dealer where they tried to figure it out to no avail.

I have a background in engineering with some electrical but I don’t have any of the tools necessary to interface with the genesis onboard and the dealer has no idea where to go from here.

I have been messing around with some testing and pulling the fuse for the main center stack fixes the issue. This is basically what we do when car sits at airport etc.

I do really like this car but does anyone have any suggestions on where to go from here for testing or had a similar problem. Pulling fuses doesn’t feel like an ideal approach to finding electrical gremlins in a car this complex

And what do you say to a potential buyer. We have a similar problem and want to sell our Genesis with only 10,000 miles, but we can't tell the buyer that it has no problems. And if it is a problem which can't be fixed, we don't know what to do. Right now we're waiting for AAA to show up to charge our newest battery (about 3 months old).

 

[EdP]

And what do you say to a potential buyer. We have a similar problem and want to sell our Genesis with only 10,000 miles, but we can't tell the buyer that it has no problems. And if it is a problem which can't be fixed, we don't know what to do. Right now we're waiting for AAA to show up to charge our newest battery (about 3 months old).

Private sale it would suck not to disclose. I'd trade it in and let the dealer worry about it.

 

[carguy75]

Hey all thanks for the ideas. Trouble I ran into with trying to check draw is when you open the door so many things turn on so every test I basically had to setup, shut the doors etc and let everything go to sleep then check periodically for latent draw. Car has been at dealer for around 40 days this last year and they still have no idea what’s going on. I realize it’s higher mileage (about 70k)but I didn’t expect this long of a problem or for them to have no tools to find this type of issue. It runs the battery dead consistently within 30-40 hours so I assumed this go around they would be able to find something but seems like they are getting nowhere. They said they called Hyundai to no avail. Feels like it would be easier to wire it like a land cruiser and just install a second battery at this point to deal with starting so I don’t have to jump it 3 times a week.


I can do a battery tender etc but that is frankly as much work as just jumping the stupid thing, unless I get fancy and wire one in so I just have to plug it in like a block heater.

Again, thanks all for the ideas. I’ll see what I can figure out if I ever see the car again. Driving this Nissan note isn’t quite the same

My guess is that you have a faulty voltage regulator/rectifier in your alternator which is draining your battery and preventing it from properly charging. I would start saving money for a new alternator when it goes out completely and display the battery icon in the instrument cluster.

 

[arcman]

A faulty alternator rectifier would be easy to check with either a DC amp clamp or infrared thermometer. That's a big ass battery in there and pulling enough current to kill it in two days would make considerable heat. If the fuse method I mentioned above didn't produce a result (unlikely), I'd start with the amp clamp or go around the car pointing the thermometer at everything that could be a possible current draw. Amazing the dealer can't track this down.

 

[Edspider]

I had this same problem about 10 months ago. Only 11,000 miles and 3 years old. It was towed three times. Dealer could not find the drain and kep the car for a few days. On the 3rd tow, they had me put in a new battery. It has been fine since then.

 

[liamlunchtray]

I'm shopping for a used '15/'16 now and have been obsessively searching listings. As such I have looked at about a million Carfax reports in the past few weeks (I'm happy to travel if its the "right" car). Anyhow, I have noticed on more than one carfax where "Battery checked" or "battery replaced" will be listed multiple times. I've seen at least a few that list multiple battery replacements. I have no clue what the cause is, but you definitely arent the only person with this issue.

 

[zape]

I think my battery is dying too.
One day I did not drive at lunch time and had to jump start to get home after work.
Measured the battery voltage at home and it was 10.8v.
Bought a CTEK 7002 charger and charged the battery for two nights
It now measures 12.6v but not sure if the battery is good - the charger is on 2nd light after 24h of charging
Will see how it start tomorrow