[alnert21212]

Hi,
I woke up this morning to a dead battery doors won’t open nothing worked. I had someone give the battery a boost and it started right away. The car is charged halfway. I understand the battery that starts the car is a separate battery. Here’s where things get interesting. The car only has 5300 miles. So the battery shouldn’t die just like that. Nothing was left on in the car. And shouldn’t the EV battery charge the small battery? Now what’s interesting is I usually use the app to remote start the car. The past couple of days The remote start would not work. I would get an error “ the car has not been started in a few days remote start unsuccessful”. Now I’ve been driving the car every day starting and stopping multiple times a day. I first I thought this is just a glitch in the app. Now I’m starting to think there’s something wrong with the car not charging the small battery. I did not receive any errorsOn the dash of battery warnings or errors. Any thoughts? Also is there a way to check the status of the small battery without hooking it up to a booster pack etc.? Thanks

 

[alnert21212]

Forgot to mention I’m in the US. New York.

Hi,
I woke up this morning to a dead battery doors won’t open nothing worked. I had someone give the battery a boost and it started right away. The car is charged halfway. I understand the battery that starts the car is a separate battery. Here’s where things get interesting. The car only has 5300 miles. So the battery shouldn’t die just like that. Nothing was left on in the car. And shouldn’t the EV battery charge the small battery? Now what’s interesting is I usually use the app to remote start the car. The past couple of days The remote start would not work. I would get an error “ the car has not been started in a few days remote start unsuccessful”. Now I’ve been driving the car every day starting and stopping multiple times a day. I first I thought this is just a glitch in the app. Now I’m starting to think there’s something wrong with the car not charging the small battery. I did not receive any errorsOn the dash of battery warnings or errors. Any thoughts? Also is there a way to check the status of the small battery without hooking it up to a booster pack etc.? Thanks

 

[knutsp]

One has to admit that the 12V system (battery, charging of it, current leakage and/or use when car off off/parked) is the weak spot of Ioniq. There are hundreds of posts about it in this forum(s). Others may say more about this. I have come to the conclusion that I recommend having a booster (12V charger) just in case. (As I also do for older fossil cars with a 12V battery of unknown or halfway bad state). Such device is cheap, simple to connect and gives almost immediate results.

My yet unconfirmed guess is that the charging voltage is not optimal for all conditions.

The 12V is needed to "boot" the main high voltage system, and for anything that works whan car off off, like entertainment, comfort and parking lights. It is not for starting up the engine and is not charged directly by an engine driven generator. The high voltage hybrid battery is charging it, and may even maintain it a few times while parked (this, in case needed, gives you a short dash alert when car is turned on).

 

[alnert21212]

One has to admit that the 12V system (battery, charging of it, current leakage and/or use when car off off/parked) is the weak spot of Ioniq. There are hundreds of posts about it in this forum(s). Others may say more about this. I have come to the conclusion that I recommend having a booster (12V charger) just in case. (As I also do for older fossil cars with a 12V battery of unknown or halfway bad state). Such device is cheap, simple to connect and gives almost immediate results.

My yet unconfirmed guess is that the charging voltage is not optimal for all conditions.

The 12V is needed to "boot" the main high voltage system, and for anything that works whan car off off, like entertainment, comfort and parking lights. It is not for starting up the engine and is not charged directly by an engine driven generator. The high voltage hybrid battery is charging it, and may even maintain it a few times while parked (this, in case needed, gives you a short dash alert when car is turned on).

So when the 12v battery is dead should the car be able to start or not?

 

[ScorpioH]

So when the 12v battery is dead should the car be able to start or not?

Sadly not.

If the 12v battery is dead there's no power going to close/activate the circuits to pull power from the high voltage battery pack. Also, sadly, there's no kind of warning to let you know the 12v is dying. On mine when the 12v was low (before I replaced) it would sometimes stall turning on and show lights to put the car in Park and or to check the regen system or some other scarry warning. When I turned off the car and turned it back on it would flash that, but then turn-on and no longer show the warnings. After driving for a bit, turning off the car and back on gave no error. I had to use my portable lithium jump starter on my car twice back in Nov. Which is what led me to think it was the tiny 12v battery. My local dealer wanted $500 just for the battery. It's a "special" size and so they want a premium. I bought an aftermarket one like a week ago and have been fine. I was out of warranty on my 12v battery. Your car sounds pretty new, next time you're at the dealer have them check it. They checked mine almost every time I was in at my insistence, but it was always 'ok'. Then they said it was dying when I had to leave the car overnight for them to install some software update, which I expected, but refused to pay their insane price for a 12v.

 

[ScorpioH]

Also, one of the times I had to jump my car was this past Nov. when I was at Zion National Park and the lows were in the upper 20s at night. Now that I think about it, I had to use my jump starter twice that weekend trip in the mornings. That's with me fully charging the car at the chargers they have at the lodge in the evenings and then moving the car to free up said charger, which should also have topped off the 12v battery. The 12v battery did not appreciate it being that "cold".

 

[chui]

So when the 12v battery is dead should the car be able to start or not?

It will not start. Around 11v + is required from the 12v battery to "boot" the systems. Once the car is "live" the power to start the engine comes from the HV battery.

 

[alnert21212]

Thanks for all the info. I’m going to have it checked out next time I bring it in for Maintenace

 

[SilverAuroraPHEV]

Hi,
I woke up this morning to a dead battery doors won’t open nothing worked. I had someone give the battery a boost and it started right away. The car is charged halfway. I understand the battery that starts the car is a separate battery. Here’s where things get interesting. The car only has 5300 miles. So the battery shouldn’t die just like that. Nothing was left on in the car. And shouldn’t the EV battery charge the small battery? Now what’s interesting is I usually use the app to remote start the car. The past couple of days The remote start would not work. I would get an error “ the car has not been started in a few days remote start unsuccessful”. Now I’ve been driving the car every day starting and stopping multiple times a day. I first I thought this is just a glitch in the app. Now I’m starting to think there’s something wrong with the car not charging the small battery. I did not receive any errorsOn the dash of battery warnings or errors. Any thoughts? Also is there a way to check the status of the small battery without hooking it up to a booster pack etc.? Thanks

status check with a car battery tester.

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[andersmo]

One has to admit that the 12V system (battery, charging of it, current leakage and/or use when car off off/parked) is the weak spot of Ioniq. There are hundreds of posts about it in this forum(s). Others may say more about this. I have come to the conclusion that I recommend having a booster (12V charger) just in case. (As I also do for older fossil cars with a 12V battery of unknown or halfway bad state). Such device is cheap, simple to connect and gives almost immediate results.

My yet unconfirmed guess is that the charging voltage is not optimal for all conditions.

Yes, there may be hundreds of posts about 12V battery problems, but taken into account that there are currently more than 100,000 posts at this forum, and 7,000 members, probably only a very tiny fraction of the Ioniq owners have ever encountered that problem. Good health is quiet.

I've certainly had my share of battery problems with my previous (petrol powered) cars. The difference is that it's much more obvious. When the battery is beginning to go bad, you can easily spot that the starter engine sounds more strained, way before everything else stops working, and there's plenty of time to take action.

Still, I completely agree that keeping a booster in your car is a very good idea, whether you've had battery problems or not. Even if you won't ever need it for yourself, you may be able to help a fellow road user in need.