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  • US ICCU Recall (aka 12V battery failure issue). Please use the following thread, this pertains to all eGMP models. Please do not create duplicate threads on this topic. Thread

12V Battery drain

54K views 163 replies 51 participants last post by  aeschylus.shepherd 
#1 ·
Hi! yesterday I had a warning on Bluelink app about the 12V battery (red icon and warning text)
Early in the morning I started the vehicle without problems and the warning is gone.

Did you have a similar issue?
Is it an app bug?

IONIQ5 RWD 73,2kWh
 
#3 ·
Likely that is warning of an automatic recharge of the 12 volt battery while car was parked. Such recharges are triggered by detecting low voltage states in the battery. An occasional warning is probably not worrying about. Lots of them is basically alerting you to high vampire current which is discharging your battery. Which should lead you to service to check for the source of high current while car is off to remedy the issue. At the least, such events shorten your battery life and at worst will strand you.
 
#6 ·
I agree. And the "bad" battery in all probability got that way from many smaller discharges since it left the factory than an electrical problem that just arose recently. I would suggest hooking up the battery to a smart trickle charger: it may not be too late to reverse the sulfation than all those smaller voltage drops caused.
 
#7 ·
Please get a BM2 battery monitor & hook it up. This will show you what's really going on to the voltages, and it will be very illuminating to see what treatment the Ioniq 5 gives the 12V. If it's the same as Konas & Ioniq 38s get, then they may not have improved their strategy, and you Ioniq 5 guys can expect a number of vampire drains leaving you with a flat battery. There's been 1 or 2 mentions already of this happening.

If they've changed the strategy (more frequent topups, topup happening when voltage getting low rather than really empty, topups lasting more than a pathetic 20 mins once/day as in Ioniq 38, something like that hopefully) then this will be more ammo to persuade them to upgrade the strategy on Konas & Ioniq originals. H & other mfrs need to learn hard & quickly from Tesla policy of trying their best to look after previous buyers, and not just shovel cars out of the door & then forget they exist.
 
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#10 ·
Please get a BM2 battery monitor & hook it up. This will show you what's really going on to the voltages, and it will be very illuminating to see what treatment the Ioniq 5 gives the 12V. If it's the same as Konas & Ioniq 38s get, then they may not have improved their strategy, and you Ioniq 5 guys can expect a number of vampire drains leaving you with a flat battery. There's been 1 or 2 mentions already of this happening.
The 12V drainage issue was addressed, in Kona at least, by software update in 2019 - my Kona checks 12V battery every few hours & charges as necessary. Although I know it was a problem before that. I’d be amazed if I5 doesn’t do that as well. I still think the most likely explanation is battery damage when 12V is isolated for shipping/storage. But we’re all speculating- I haven't seen anything definitive at this stage.
 
#11 ·
Hopefully I5 has the 4-hourly, or is it 6-hourly checks the Kona does. But Ioniq 38 doesn't! And we've heard of some I5 flat batteries happening. Until someone with an I5 puts a BM2 on the 12V we won't know what H are trying these days ...
 
#12 · (Edited)
So that your 12V battery discharges as little as possible, when you get into the car, you must always press the brake pedal and turn the ignition on until you see green ”READY”, so that the DC/DC converter is switched on, which charges your 12V battery with 14V. Either you have to go to EV in the infotainment screen -> gear icon right -> scrolls down to see Activity mode and set it on. This does the same, without having to push the brake and put it in the ready position.
NOTE:
  • On an ICE version you also let run the engine so that the alternator charges the 12V battery to prevent draining, here on an EV you must only switch the DC/DC converter on to charge your 12V battery.
  • the electric motor(s) doesn't run when you are in the READY state as long as your gear selector is in the P position.
  • As soon as you put the ignition key on so that the green "READY" is on, the activity mode is automatically turned off.

Automotive parking light Wheel Tire Automotive lighting Hood
 
#13 ·
So that your 12V battery discharges as little as possible, when you get into the car, you must always press the brake pedal and turn the ignition on until you see green ”READY”, so that the DC/DC converter is switched on, which charges your 12V battery with 14V. Either you have to go to EV in the infotainment screen -> gear icon right -> scrolls down to see Activity mode and set it on. This does the same, without having to push the brake and put it in the ready position.
NOTE:
  • On an ICE version you also let run the engine so that the alternator charges the 12V battery to prevent draining, here on an EV you must only switch the DC/DC converter on to charge your 12V battery.
  • the electric motor(s) doesn't run when you are in the READY state as long as your gear selector is in the P position.
  • As soon as you put the ignition key on so that the green "READY" is on, the activity mode is automatically turned off.
Good info Jaz but how long does the 12v auxiliary battery get charged for at 14v.

As Andy @HandyAndy mentioned before, a short charge on a depleted wet acid battery is not going to make much difference at all (if any).

Does anyone know if the I5 has a split charge relay fitted to help maintain the 12v battery when the traction battery is being charged via an external power hookup.
 
#17 ·
The 12.7v was taken when the car was fully switched off.

The point I make (and in synch with @HandyAndy) is that short bursts of charge while the system is ready/on is not going to make a huge difference to the Battery itself.

Also, if the actual charge being provided from the traction battery is only 13.5v (+) then that's insufficient IMO to support a quality charge for a wet battery. I would personally want a 14.1v constant charge for standard wet batteries and 14.3v if the auxiliary battery was derived from an EFB technology and 14.7/8v for AGM etc.

All the best,

SB
 
#18 ·
12.7V is 100% OK for a battery with everything switched off.
The alternator of an ICE car charges on average between 13.5V and 14V, sometimes a little bit higher, but 14V is more than enough to charge the battery correctly. Above 14 volts is even nefast for the 12V battery life.
 
#20 ·
I hope they will replace the close button too and check the charge port door if it is not deformed. Because sometimes you push too hard to try to open this charge door. If the button is faulty and stay clicked or the door is deformed and continue to push on the close button, it is normal that the 12V battery drains.
 
#21 · (Edited)
I hope they will replace the close button too and check the charge port door if it is not deformed. Because sometimes you push too hard to try to open this charge door. If the button is faulty and stay clicked or the door is deformed and continue to push on the close button, it is normal that the 12V battery drains. It is not always the control unit.
Conclusion: if you feel that you have to push too hard to open your charge door, use your smart key or the voice control.
 
#23 · (Edited)
There is absolutely no excuse for the 12Vbattery to go flat when there is a 72 kWh backup battery that is easily connected to it. In fact I've seen in the Tesla Model Y manual that if you inadvertently leave something plugged into a 12V socket it will not run down the 12V battery.

Perhaps there is some 'shipping mode' that defeats this backup functionality so you don't end up with a drained traction battery at the destination dock, and this 'shipping mode' has not been disabled by the dealer?

Certainly there is the capability of determining what the drains are on the 12V battery, individually and in total, in much the same way Task Manager in Windows keeps track of what apps are using what resources? This is not that hard.

The fact that all this mystery exists is unacceptable. It's too easy to have the diagnostics in place to show the owner what's what.
 
#24 ·
I entirely agree with you, and I'm totally puzzled by the way the 12V battery is handled (i.e. not handled) in the IONIQ 5.
I'm sitting in a car I payed €60000+ for, loaded with microprocessors chrunching and showing all kinds of data.
But if I want to check the real state of my auxiliary battery, I have to open the hood and use my multimeter (or buy one).
The only alternative is to start the BlueLink app and see if the battery state shows "OK" (sometimes even not displayed at all?).
This "OK" on/off info does not tell me much. Why and when does it trip and say "NOTOK"? Most likely when I close the app and go to bed ...

All over this forum we have seen what a vital component the 12V battery is, and how critical it is for the whole system when going flat (which it shouldn't do).
As you say, it's too easy to have the diagnostics in place, and the 12V battery should absolutely have a menu of its own both in the infotainment and BlueLink app.
I myself would surely check such data and historical graphs frequently, and this is actually now on top of my christmas wishlist to Hyundai!
 
#25 ·
My I5 AWD is on the high seas due in the UK mid Jan. I chose the AWD as I build electric boats and have to tow them, let them down the slipway then pull them out again. All are powered by lead acid batteries.

I have been following the problems with the 12v battery for several months and there has been a lot of good advice given. These notes will hopefully add a bit more useful information.

The design of the original batteries used to start an ICE car consisted of a large number of flat plates in a wet flooded case that gave the maximum surface area. This provided the high cranking amps to start the engine and then all circuits were supplied by the alternator. With the advent of stop/start technology it was found that these batteries were not robust enough so manufacturers turned to AGM batteries. AGM stands for Absorbent Glass Mat and if you cut a battery in half (please don’t !) it looks like a Swiss Roll. They are widely used in the standby power industry and solar panel systems. The good news with these batteries is that they are both robust, sealed and have a very low rate of self discharge. You can leave them disconnected for a year without loosing much charge. The bad news is that you must not discharge them below 50% SOC or you shorten the battery life. So those people who have suffered with flat batteries will have done major damage. All lead acid batteries hate being anything less than fully charged. If left part charged the life is reduced. Always best to leave them on Float at about 13.5v. Hyundai’s software should do this.

Life with a lead acid battery is all one way – from the day you buy it to the day you replace it. If you abuse the battery in any way you just go down the road faster. There is nothing you can do to go back. Don’t believe charger claims about reconditioning. It will not work on these small 12v batteries, as I have proved with a professional discharger. I have customers who have kept their batteries for 13 years by being careful and others that have destroyed their pack in 2 years.

I will be fitting a BM2 monitor from day one, but for those wanting to present evidence of zombie discharges destroying their batteries there is a small, nifty, easy to use USB data logger made by Lascar Electronics, the EL-USB 3.

Not cheap at £60 but it is very easy to setup it to measure over any timescale from a few hours to a year. You just plug it into the laptop to download the data. You can present either by a graph with volts, date and time or you can enter it into a spreadsheet. Here is an example. I have also used the logger to prove that a boatyard didn’t recharge a boat over winter storage and so destroyed the battery pack and were liable.
Rectangle Slope Font Parallel Circle
 
#28 ·
I will be fitting a BM2 monitor from day one, but for those wanting to present evidence of zombie discharges destroying their batteries there is a small, nifty, easy to use USB data logger made by Lascar Electronics, the EL-USB 3.

Not cheap at £60 but it is very easy to setup it to measure over any timescale from a few hours to a year. You just plug it into the laptop to download the data. You can present either by a graph with volts, date and time or you can enter it into a spreadsheet. Here is an example. I have also used the logger to prove that a boatyard didn’t recharge a boat over winter storage and so destroyed the battery pack and were liable.
View attachment 37314
The BM2 keeps a record of the battery state going back days and weeks.
 
#30 ·
The BM2 is a very good data logger but it has 2 limitations.
1. It only stores the last 15 days of voltage readings.
2. The only way I can find to export the data is in a screengrab.

This is why I also use the EL-USB3. You can set it to record for as long as you like and then export the data either as a graph or into a spreadsheet with each voltage reading date stamped. As I posted, I used this information to get a replacement battery pack costing over £2000 for a client due to negligence by a boatyard over a winter storage period. For ongoing 12v problems where the AGM 12v battery is continually discharged below 50% SOC so will have its life shortened, the EL-USB3 provides solid evidence that the battery should be replaced under warranty.

Regarding reconditioning, I have been building electric boats with various lead acid batteries for 25 years. Customers often try a reconditioning option to save money but I have never seen it work. The batteries you CAN recondition are the large, wet 2v cells used on forklift trucks. This involves emptying, flushing, refilling and connection to a very expensive bit of kit for the recon. The only way you can measure if a recon works is by doing a full, measured discharge to test the actual battery capacity.
 
#31 · (Edited)
The BM2 is a very good data logger but it has 2 limitations.
1. It only stores the last 15 days of voltage readings.
2. The only way I can find to export the data is in a screengrab....
The BM2 actually says it stores up to 35 days of data, and its probably a bit more convenient to download data to your phone just by opening the app whilst in or next to the car.
It also looks like your phone stores far more than this - just checked my phone & it still has the data from when I installed it in early November.
Perhaps you meant that you can only display up to 15 days of data at one time

I'm not saying the EL-USB-3 doesn't have its uses, (as long as your a windows user), but for most people the BM2 would be a more convenient option - and I can just about handle screenshots
Font Terrestrial plant Parallel Technology Grass


The RAC recently did an interesting feature on Smart chargers & battery conditioners - Think they liked them
My CTEK unit kept my old Evoque's battery going for a full 4 years after the car reported it was on its way out
 
#40 ·
If you don't know what to ask for New Year, ask for a good battery charger, to keep your I5 battery in optimal condition.
  • You have boost chargers, to quickly help you to start an ICE engine with an empty battery, but I think this can be dangerous for the electronic units in the case of EV's
  • you have trickle chargers to help maintain the battery in optimal condition
  • you have normal battery chargers that need some time to slowly and safely charge your 6/12/24V battery.
There are a lot of normal battery chargers on the market, but I opted for BOSCH because they have a lot of technical automotive knowledge, produces most of the electronic units and have their own batteries.
Depending on your budget you can opt for the :
- Bosch C1 charger for 12V car batteries also with EFB technology (order nr 0 189 999 01M).36.33€
- Bosch C3 charger for 6V two-wheel and 12V car batteries also with AGM and EFB technology (0 189 999 030) 59.00€-> 36.41€
- Bosch C7 charger for 12V and 24V Lead-acid, AGM, WET, GEL and open VRLA batteries (0189 999 070) 77.39€
the BOSCH C7 battery charger for the following advantages and features :
C1/C3/C7
  • completely microprocessor-controlled slow start increase of current depending on the state on the battery
  • Full automatic charging control
  • no risk of overcharge
  • one-button control
  • spark protection
  • short circuit protection
  • reverse polarity protection
  • overheating protection
  • automatic trickle charging when the battery has been fully charged
  • dust and splash-waterproof IP65
C3/C7
  • charge also AGM batteries
  • memory function (C3 and C7)
  • possibility to connect permanently a wire loom to the battery with fuse and dust/splash-waterproof connector to let installed when the battery terminals are not so good accessible (ioniq 5), so that you just have to plug in a connector to start charging (C3 and C7)
C7 only
- charges also GEL and open VRLA batteries
- power supply 13.6V/5Amp so that you can replace the battery without losing all memories
- regeneration function for deeply discharged batteries

----------------------------------------------------------------------------------------------------------
C1

Adapter Gadget Font Audio equipment Cable

----------------------------------------------------------------------------------------------------------
C3
Font Gadget Cable Audio equipment Wire

----------------------------------------------------------------------------------------------------------
C7
Gadget Tool Cable Font Electrical wiring
 
#54 ·
If you don't know what to ask for New Year, ask for a good battery charger, to keep your I5 battery in optimal condition.
  • You have boost chargers, to quickly help you to start an ICE engine with an empty battery, but I think this can be dangerous for the electronic units in the case of EV's
  • you have trickle chargers to help maintain the battery in optimal condition
  • you have normal battery chargers that need some time to slowly and safely charge your 6/12/24V battery.
There are a lot of normal battery chargers on the market, but I opted for BOSCH because they have a lot of technical automotive knowledge, produces most of the electronic units and have their own batteries.
Depending on your budget you can opt for the :
- Bosch C1 charger for 12V car batteries also with EFB technology (order nr 0 189 999 01M).36.33€
- Bosch C3 charger for 6V two-wheel and 12V car batteries also with AGM and EFB technology (0 189 999 030) 59.00€-> 36.41€
- Bosch C7 charger for 12V and 24V Lead-acid, AGM, WET, GEL and open VRLA batteries (0189 999 070) 77.39€
the BOSCH C7 battery charger for the following advantages and features :
C1/C3/C7
  • completely microprocessor-controlled slow start increase of current depending on the state on the battery
  • Full automatic charging control
  • no risk of overcharge
  • one-button control
  • spark protection
  • short circuit protection
  • reverse polarity protection
  • overheating protection
  • automatic trickle charging when the battery has been fully charged
  • dust and splash-waterproof IP65
C3/C7
  • charge also AGM batteries
  • memory function (C3 and C7)
  • possibility to connect permanently a wire loom to the battery with fuse and dust/splash-waterproof connector to let installed when the battery terminals are not so good accessible (ioniq 5), so that you just have to plug in a connector to start charging (C3 and C7)

C7 only
- charges also GEL and open VRLA batteries
- power supply 13.6V/5Amp so that you can replace the battery without losing all memories
- regeneration function for deeply discharged batteries

----------------------------------------------------------------------------------------------------------
C1

View attachment 37701
----------------------------------------------------------------------------------------------------------
C3
View attachment 37702
----------------------------------------------------------------------------------------------------------
C7
View attachment 37703
Can any of them be used to jump start an I5 with a dead 12V battery? I suppose only in the garage if at all?
 
#41 ·
I do not think this is required. The Ioniq 5 does maintain the 12v battery from the HV battery as I can clearly see it in operation with my BM2 battery monitor. By all means get a battery ‘jump starter”, but then I always had one with my ICE cars.

Be aware of what causes loading of the 12v. In particular do not sit in the car with systems on unless in Utility or Ready Mode. Also note the warnings in the manual such as:
a. Do not continue depressing the brake pedal if the " " indicator is OFF. The battery may be discharged.
b. The power tailgate can be operated when the vehicle is not running. However, power tailgate operation consumes a large amount of eclectic power. To prevent the battery from being discharged, do not operate it excessively (for example, more than 5 times repeatedly).
 
#42 ·
Yes I know but I repeated maybe 20 times to put the car directly in READY or UTILITY mode to charge your 12V battery, but a lot of the owners seems to have drained batteries because of for example charge door issues, so I thought to advise them to have a good and safe battery charger at home to keep the battery in optimal condition or charge the completely drained battery.
 
#48 ·
Newest ICE cars have also a battery charging management controlled by the engine control unit that regulates the output of the alternator to charge the 12V battery with pulses rather than continue supplying a high voltage of 13.6-14.2V, which is better for the battery life time. The new EV does the same with BMS unit controlling the DC/DC output by supplying pulse controlled charging of the 12V battery.
 
#49 ·
Yes, I discovered to my dismay accompanied my sister to pick up her Subaru (ICE with dead battery after one year) that her charging was metered by miles driven (before the firmware update a charge didn't start until a trip of 20 miles!) and then a timed charge was administered. Service manager said it was a change in that model year because the alternator could not provide full charging voltage full time and still power the rest of the electronics (the infotainment unit being the biggest culprit). To me the engineering fix for that should be a higher output alternator, not a battery killing intermittent charging BMS algorithm. And if BEV manufacturers insist on speccing lead acid batteries, perhaps they should install an alternator to keep the batteries healthy. Modern cars are rather dismaying in some ways for sure.
 
#50 ·
Some interesting behaviour today. I returned home from a short 20 mile ish drive and parked the car on my driveway. About 5 mins later I noticed that the front flaps were open. Checked the battery and it had just started charging from the HV battery. About 5 mins later the flaps closed and the battery charging had stopped. Then went out for a short 40 min walk and on retunr saw that the flaps were again open and the 12v was again charging. Really no idea of what criteria the system uses to decide to start charging!
 
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