12V battery

[Bob Long]

I am starting this thread with my observation today.
The yellow light was on(the one between the H on the front badge) after 4+ hours of being parked.
I remember something in the manual that was an indicator of systems active in the vehicle, so when I got home I measured the 12V directly at the battery terminals and it was 12.36 V.
Put car in run mode and the voltage was 14.76, left on 15 minutes and rest voltage was 12.67.(Fluke 97 meter)
Excellent! The big battery charges the little one but still have to find the low and high threshold of when that takes place,
Have not used much of accessories so it seems a little early( 3 weeks ownership) for the 12 V battery to be that low.
I will monitor, but at least its comforting in the fact that if the voltage is low (indicated by the yellow light in the front badge) you can put into run mode with the electric brake on and top off the battery(no external battery maintainer required).
From previous ev experience I have found the minimum operating voltage without any software hic-ups is 12.6 V

Hi, I have had 12V battery issues with my 3 EV cars since 2015. The 2014 Tesla Model S had to have a new 12V battery and so did our 2016 Kia Soul. We now have the Kona since May 2019 and this also went completely flat on two occasions. It was so dead that it wouldn’t take a charge until the road assistance guy boosted the battery for about 5 minutes. We have the battery saver+ on, so why didn’t the yellow light come on inside the badge on the front? We are taking the car to the dealer here in Norway in two weeks time to get all the electrics checked. Why on earth don’t manufacturers put a 12V Display on the Screen in front of you showing you the charged state of the battery? Your mobile phone displays how much battery is left, so why not with the 12V battery? It would be a much simpler way than to check the battery with a Volt meter. There are so many 12V battery issues with electric cars that it would be good to know how much battery is left, the same showing you the range you have with the main battery!

 

[apu]

It was so dead that it wouldn’t take a charge until the road assistance guy boosted the battery for about 5 minutes.

Yes I experienced this on my last dead 12V battery event. I had this false sense of security keeping my lithium battery booster in the car. Unfortunately when the lead acid battery voltage hits a certain low voltage threshold the "smart" circuitry in the booster faults out and make the lithium booster essentially useless. So now I have to find something less smarter like booster cables, what a pain.

 

[electriceddy]

Hi, I have had 12V battery issues with my 3 EV cars since 2015. The 2014 Tesla Model S had to have a new 12V battery and so did our 2016 Kia Soul. We now have the Kona since May 2019 and this also went completely flat on two occasions. It was so dead that it wouldn’t take a charge until the road assistance guy boosted the battery for about 5 minutes. We have the battery saver+ on, so why didn’t the yellow light come on inside the badge on the front? We are taking the car to the dealer here in Norway in two weeks time to get all the electrics checked. Why on earth don’t manufacturers put a 12V Display on the Screen in front of you showing you the charged state of the battery? Your mobile phone displays how much battery is left, so why not with the 12V battery? It would be a much simpler way than to check the battery with a Volt meter. There are so many 12V battery issues with electric cars that it would be good to know how much battery is left, the same showing you the range you have with the main battery!

That and a pack temperature gauge! (at least concerning my Kona EV - not sure if that is on Tesla)

 

[KiwiME]

...when the lead acid battery voltage hits a certain low voltage threshold the "smart" circuitry in the booster faults out and make the lithium booster essentially useless.

It must be faulting on overcurrent rather than actively limiting the current as the LDC does when hit with a deflated battery. If you placed a resistance in series initially it might carry on until the charge picks up a bit. I'm thinking of perhaps a couple of 55W headlight bulbs in parallel for example.

 

[apu]

It must be faulting on overcurrent rather than actively limiting the current as the LDC does when hit with a deflated battery. If you placed a resistance in series initially it might carry on until the charge picks up a bit. I'm thinking of perhaps a couple of 55W headlight bulbs in parallel for example.

Its possible but at the same time I know that part of its safety logic needs to sense a minimum voltage(what that value is I do not know) before it allows current to flow.

 

[Vince08]

I have not had any 12V battery problems on my 6 months old car but I am not taking any chances. I have just installed DIY a retro-look voltmeter on my dashboard so that I could monitor both the resting or charging voltage with a quick glance. It also serves to add a custom look to an otherwise bare looking dash top.

 

[electriceddy]

View attachment 8933 View attachment 8934 View attachment 8935 I have not had any 12V battery problems on my 6 months old car but I am not taking any chances. I have just installed DIY a retro-look voltmeter on my dashboard so that I could monitor both the resting or charging voltage in a quick glance. It also serves to add a custom look to an otherwise bare looking dash top.

Looks nice with the floor lighting as well. It must have been difficult to get wiring to that portion of the dashboard. Where did you run the wiring to feed the meter, from the battery itself?

 

[Vince08]

I ran the wires inside the small gap between the dashboard and windscreen. It then goes directly into the fuse box just beside the steering column. If time permits, I will compile the images I took during the installation and then upload into YouTube, similar to the one I did for my LED headlight change.

 

[apu]

Well I got the call today after nearly a week at the dealers that my Kona's 12v battery was replaced in context to recent no start condition that I experienced 2 days after my traction motor replacement. Basically the car would tell me to put my foot on the brake to start every time I tried to do so without actual start. Went down, thanked my service advisor and I headed to a shop literally 5 minutes away, stopped briefly and the car would not start again, giving me the "foot on brake to start" message. I used my booster pack and it started, drove to dealer, turned if off and tried starting with no joy. Sadly I reclaimed the loaner Accent as it seems the Kona will be in the shop a few more days. I gotta wonder if the DC to DC converter is not functioning properly. It might be coincidental to motor swap or I suppose it could just be a loose connection, that or its always been a problem and that is why my old 8 month old 12v battery gave up the ghost. I tried to talk to the tech but he was too busy for me. Probably just as well, as they always look at me like I'm crazy when I suggest something diagnostic. Oh well, at least I have a loaner.

 

[electriceddy]

Well I got the call today after nearly a week at the dealers that my Kona's 12v battery was replaced in context to recent no start condition that I experienced 2 days after my traction motor replacement. Basically the car would tell me to put my foot on the brake to start every time I tried to do so without actual start. Went down, thanked my service advisor and I headed to a shop literally 5 minutes away, stopped briefly and the car would not start again, giving me the "foot on brake to start" message. I used my booster pack and it started, drove to dealer, turned if off and tried starting with no joy. Sadly I reclaimed the loaner Accent as it seems the Kona will be in the shop a few more days. I gotta wonder if the DC to DC converter is not functioning properly. It might be coincidental to motor swap or I suppose it could just be a loose connection, that or its always been a problem and that is why my old 8 month old 12v battery gave up the ghost. I tried to talk to the tech but he was too busy for me. Probably just as well, as they always look at me like I'm crazy when I suggest something diagnostic. Oh well, at least I have a loaner.

The "foot on the brake" message is new to dead 12 V battery symptoms. Sounds like some sensor is not working possibly in the brake assy itself. Of course it would have been beneficial to actually know the residual voltage level when the message came on. Hopefully it can be traced with ease and doesn't develop into another intermittent type issue.

 

[cmwade77]

Well I got the call today after nearly a week at the dealers that my Kona's 12v battery was replaced in context to recent no start condition that I experienced 2 days after my traction motor replacement. Basically the car would tell me to put my foot on the brake to start every time I tried to do so without actual start. Went down, thanked my service advisor and I headed to a shop literally 5 minutes away, stopped briefly and the car would not start again, giving me the "foot on brake to start" message. I used my booster pack and it started, drove to dealer, turned if off and tried starting with no joy. Sadly I reclaimed the loaner Accent as it seems the Kona will be in the shop a few more days. I gotta wonder if the DC to DC converter is not functioning properly. It might be coincidental to motor swap or I suppose it could just be a loose connection, that or its always been a problem and that is why my old 8 month old 12v battery gave up the ghost. I tried to talk to the tech but he was too busy for me. Probably just as well, as they always look at me like I'm crazy when I suggest something diagnostic. Oh well, at least I have a loaner.

A loaner vehicle is not the same as having your own vehicle and make sure they acknowledge that your warranty will be extended by the length of time it was in the shop.

 

[electriceddy]

A loaner vehicle is not the same as having your own vehicle and make sure they acknowledge that your warranty will be extended by the length of time it was in the shop.

That would be like opening a can of worms and possibly have a negative affect with the dealership. If the dealership has been providing good service (which apparently it has with the motor replacement) up to this point, why rock the boat? This is a new car with new tech, and I am sure the repair Techs are learning along with the rest of us. Additionally not always clear repair documentation for provided on Hyundai's end either, I have seen some of it on their computers and it is not always clear and specific.

 

[cmwade77]

That would be like opening a can of worms and possibly have a negative affect with the dealership. If the dealership has been providing good service (which apparently it has with the motor replacement) up to this point, why rock the boat? This is a new car with new tech, and I am sure the repair Techs are learning along with the rest of us. Additionally not always clear repair documentation for provided on Hyundai's end either, I have seen some of it on their computers and it is not always clear and specific.

Not sure about where you are, but in California that is the law.

 

[electriceddy]

Not sure about where you are, but in California that is the law.

Here ( in Canada) the warranty is starts at the "in service date" which cannot be changed by the dealership, so why try to push that upon a dealer who presumably is probably doing their best job at repairing the vehicle with the tools given them. If one is uncomfortable with the time that is required or any delays that may be involved there are processes available , however if one wants to escalate, than my suggestion is to present any discrepancies to Hyundai Corporate and proceed from there. That is what we have to work with here, generally seems to work pretty well.

 

[eastpole]

The "foot on the brake" message is new to dead 12 V battery symptoms. Sounds like some sensor is not working possibly in the brake assy itself.

I recently had the Kona refuse to start after a weekend camping trip, claiming I did not have the key in the car. I was worried about the key battery being dead, but the OTHER KEY did the same thing. I tried using the contact feature of the key. Didn't start either, although it lit up part of the dashboard. Then it would chime and turn off again.

While waiting for a tow truck and wondering what the hell we were going to do with our camping cooler, children, tents, etc I chatted with a guy leaving the campground in his minivan. Turns out his other car is a Prius and he had experienced weird non-meaningful messages whenever his 12V battery ran too low. Based on that, I asked him to give me a 12V boost and the car started up just fine. We cancelled the tow and drove home uneventfully.

Now I have a Bluetooth voltmeter riding permanently on the auxiliary battery, so at least next time I will know what the problem is. Irritatingly, this was *right after* doing the BMS update that has been mandated. I don't think they killed my battery; I'm pretty sure someone left a dome light on for the weekend. I'm aware other EVs share this Achilles' heel ,but I'm still annoyed by fact that we have a 400 V battery with 67 kWh of energy in it and can't seem to get a 12 V battery with <1 kWh to stay at a reasonable state-of-charge. :|

 

[cmwade77]

Here ( in Canada) the warranty is starts at the "in service date" which cannot be changed by the dealership, so why try to push that upon a dealer who presumably is probably doing their best job at repairing the vehicle with the tools given them. If one is uncomfortable with the time that is required or any delays that may be involved there are processes available , however if one wants to escalate, than my suggestion is to present any discrepancies to Hyundai Corporate and proceed from there. That is what we have to work with here, generally seems to work pretty well.

Yeah, that is the start of ours and it used to be limited to that, but too many dealerships were taking months to repair cars here, so they changed the law requiring that the warranties be extended by the amount of time they are in the shop and add some mileage as well.

 

[cmwade77]

I recently had the Kona refuse to start after a weekend camping trip, claiming I did not have the key in the car. I was worried about the key battery being dead, but the OTHER KEY did the same thing. I tried using the contact feature of the key. Didn't start either, although it lit up part of the dashboard. Then it would chime and turn off again.

While waiting for a tow truck and wondering what the hell we were going to do with our camping cooler, children, tents, etc I chatted with a guy leaving the campground in his minivan. Turns out his other car is a Prius and he had experienced weird non-meaningful messages whenever his 12V battery ran too low. Based on that, I asked him to give me a 12V boost and the car started up just fine. We cancelled the tow and drove home uneventfully.

Now I have a Bluetooth voltmeter riding permanently on the auxiliary battery, so at least next time I will know what the problem is. Irritatingly, this was *right after* doing the BMS update that has been mandated. I don't think they killed my battery; I'm pretty sure someone left a dome light on for the weekend. I'm aware other EVs share this Achilles' heel ,but I'm still annoyed by fact that we have a 400 V battery with 67 kWh of energy in it and can't seem to get a 12 V battery with <1 kWh to stay at a reasonable state-of-charge. :|

Shouldn't the dome light turn off automatically after a certain amount of time to prevent this from occuring?

 

[KiwiME]

I'm aware other EVs share this Achilles' heel ,but I'm still annoyed by fact that we have a 400 V battery with 67 kWh of energy in it and can't seem to get a 12 V battery with <1 kWh to stay at a reasonable state-of-charge. :|

It's a catch-22 of engineering challenges that will eventually be resolved, if it hasn't already by the latest EVs on the market. It says something that the leading innovator of tech, Tesla, suffer similar issues although no-doubt they could solve this first. I'm pretty sure that the Model 3 has a DC-DC inside the traction battery pack which implies it can operate without the main contactor closed.

 

[cmwade77]

It's a catch-22 of engineering challenges that will eventually be resolved, if it hasn't already by the latest EVs on the market. It says something that the leading innovator of tech, Tesla, suffer similar issues although no-doubt they could solve this first. I'm pretty sure that the Model 3 has a DC-DC inside the traction battery pack which implies it can operate without the main contactor closed.

Why can't it take a page out of the Ford CMAX Energi playbook? Basically, if the 12 volt battery is dead, it automatically takes a bit of power from the High Voltage battery to recharge it enough to start the car.

 

[electriceddy]

Shouldn't the dome light turn off automatically after a certain amount of time to prevent this from occuring?

As per manual:
The interior lamps will automatically go off approximately 20 minutes after the vehicle is turned off and the doors closed. If a door is opened, the lamp will go off 40 minutes after the vehicle is turned off, If the doors are locked by the smart key and the vehicle enters the armed stage of the theft alarm system, the lamps will go off five seconds later.
Nothing mentioned about the action if Utility mode is selected.