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Have you left yours without charging for 3 or 4 days? Mine was fine up until a month ago when I left it without a charge for 4 days. It was dead. I think I got mine about the same time as you.
I only charge up every week unless I have a long trip planned. This past 3 weeks it hasn't needed a charge and fired up instantly when I took it out of the garage to give it a thorough clean and silicon/wax treatment.
 

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I'm hopeful that @wizziwig will know what happens if Battery Saver is unticked.

Apart from all this, I wonder if a particular battery manufacturer's batteries are at fault, moreso than the car ?
 

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I think the problem is somewhere else than just top-up when the car is stationary (aux saver+). Or maybe it's the whole bunch of problems...

I have Kona EV and often I was unable to start the car after it has just been driven.
  • Car starts ok in the morning, my wife takes kids to school, 15 minutes later she returns to the car unable to unlock the door.
  • Or I take car to local shop, come back with groceries 30 minutes later and need to use jump start to power on the car.
This happened very frequently in last few weeks leading up to Hyundai replacing 12v battery (they run test on it and it still passed fine). You may think - maybe the car electronics consume more power than DC>DC converter can deliver when driving (lights, defrost, heating, radio). No, because i have also driven the car constantly for 27hrs (5 recharging stops + ferry) in winter and had no problems afterwards. I have also driven other variations: 900miles over two days; 3000K miles over 15 days around Europe; sometimes car is unused for 2-3 weeks and it is till fine. Yet other times (used the day before, parked overnight, started next day, and it died shortly after) it has mind of its own.
 

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I have read about these problems in several forums Ioniq, Kona and MG ZS. It appears to be a usage problem. I believe people are doing many short journeys which is not given the 12v battery enough time to charge. Over time this will depleat the battery to the point it won't switch on. The pattern illustrated above shows this longer journeys no problem short journeys problems bit probably not happening the next day after a long journey. What people aren't saying is whether they put a charger on the 12v battery to fully charge it when this happens. If they don't then the issue will occur frequently.
What I can't fathom out is when that battery auto saver comes on and how long for and if the battery is charged if people plug in overnight. I have an Ioniq my battery saver was set on when I received it in March. People have reported before that a message is displayed it the auto saver has charged the battery I have not seen this message yet even during the lock down
 

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I always display the parameters of 12V battery while driving (Car Scanner ELM OBD2 app), and the charging/discharging curve of 12 V battery is inconsistent and hectic.
I could not figure out the charging strategy of 12V battery when car was driven.
Unfortunately the SOC of 12V battery is not available, just the voltage and current.

Screenshot_20200407-111125.png Screenshot_20200407-111210.png Screenshot_20200407-111303.png
 

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No, I don't believe it is short journeys that causes flat 12v battery.

Once I returned from long journey (Amsterdam>London) and the car failed the very next morning on my drive. Yet other times I had no problems at all.
We have also done lots of short journeys over consecutive days (school runs) in previous winter with no problems whatsoever. I have taken the car to ski resort where it was only doing short trips (hotel > ski lift) over many days in sub-zero temperatures and no problems either.

The problems first started when car was 8 months old. Then happened more and more frequently as the weeks passed. I looks like battery deteriorated somehow (Hyundai blamed a lot of things - once they told me that calibration sensor was showing 255% charge when they charged battery to 100% externally). But I know several other people (my dashcam installer with younger eNiro and another guy with 2020 Ioniq) where problems started just after few months and 2 weeks respectively.
Also US Kona FB group is full of people who carry jumpstarter in the car.

Somebody on Kona forum here sent and recommended others to send email to Hyundai customer care just to make them aware of the problem. Maybe enough pressure would start more proper investigation into this fault. So when I sent my email I got a response: "...we have never heard of this problem before"
Yeah, right! :rolleyes:
 

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I have been trying to do some measurements of the current being drawn by the car using a mini AC/DC clamp meter that has a 4A DC range. The positive terminal from the battery splits into two feeds. With the bonnet up and the car locked I get current readings of around 1.8A and 50mA from these feeds. As the bonnet is open the driver's display is lit up to show the bonnet is open. So far I have not been able to come up with a simple method of disabling the bonnet open microswitch that is built in to the closing mechanism. I have not been able to separate the connector to the microswitch to insert a shorting link. If the bonnet is open then a charger with a capability of greater than 2A would seem to be required to overcome the discharge current of the car. I currently have the bonnet closed and am charging the battery with a NOCO genius5 charger to see what happens. It initially started charging with 25% flashing but has rapidly progressed to 75% charged (in around 30 mins.) I need to give further thought to disabling the bonnet switch.
 

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Does every one with the problem have a dash cam? Seems to be a lot of mentions of dash cams in this thread.
I don't have the battery issue, and quite pleased about that too as the issue with the motor needing replacing seemed bad enough.

It seems to me that there is an issue that Hyundai/Kia are trying to ignore. Does it need a collective effort to push back a little more forcefully. If you can't trust the car to start every time when it is nearly new there's a problem that needs sorting. If they can't sort it then the car isn't fit for purpose and they should be arranging some way of getting the car repaired or replaced.
It isn't the customers responsibility to work out what the problem is, the manufacturer gives a 5/7 year warranty and they need to honour that.
 

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The battery has fully charged and switched to maintenance mode after a couple of hours. So far I have not experienced the starting problem but charged the battery anyway as the car is currently only being used for a very short trip once a week. My high voltage battery is currently at 55% charge which is, I believe close to optimum for non use. I have not charged the whole car for over three weeks now and whilst not being used I will only charge to 50% when a charge is required. I do have a dash cam fitted but this only powers on when the car is ready to drive. From reading previous posts I think the dash cam issue is being used as an excuse by dealers to avoid proper investigation. I had a similar problem with a Land Rover dealership when I had a battery problem in a previous car.
 

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No dash cam installed but one sitting on the window sill in the spare room waiting. I have got other stuff plugged into the USB constantly but every indication from those things is they are powered off when the car is switched off and locked. Think the dash cam thing is just an excuse as @George56 says. I haven't specifically had a starting problem, just the warning signs of the battery saver being on which spooked me.

Here's a slightly left field thought. What happens when the battery saver switches on? Does it light up other circuits perhaps feeding them and anything plugged into them. If the battery saver feed is relatively low power, you could end up with more being drained than the saver was putting in, thus having exactly the opposite effect to that intended? Anyone got a dash cam they could check for odd ghostly overnight recordings?

I actually had this weird behaviour in my i3 but linked to the App. The car would be asleep on the drive and when I sent an OTA change to its charge profile, it would light up everything and my dash cam would start recording. I only noticed it by accident while looking for a particular recorded event on the card.
 

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Am I right in thinking that those who have given their 12V batteries a long, slow recharge/topup/balance, not just a simple charge, have not had a problem afterwards? If so would such a charge recalibrate the battery saver circuit to a higher/longer/better configuration which works?
 

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Am I right in thinking that those who have given their 12V batteries a long, slow recharge/topup/balance, not just a simple charge, have not had a problem afterwards? If so would such a charge recalibrate the battery saver circuit to a higher/longer/better configuration which works?
Yes.

This problem has been around in all EVs for years. Five years ago I had an early Nissan Leaf that locked me out but recovered when the 12v DC battery was charged. There was much discussion in various forums and others reported the same thing. Some insisted on a replacement 12v battery and many were fitted under guarantee. There must have been a dozen threads in here on this subject already.

Back then there were two schools of thought. One was to get angry at Nissan and demand action. Which they resisted. Other manufacturers have also taken this stance over the years. The real cause has never been fully identified.

Others owners concluded that life was too short to be constantly worried about the cars 12v battery running down and began to use preventative maintenance by attaching a smart charger overnight once a month. Whether the car seemed to need it or not. It is important to use a smart charger as a dumb one or trickle charger can overcharge and cause other damage.

I fell into the second group and the same battery that initially failed went on to give trouble-free service for three further years until the PCP ended. I carried on with this monthly regime with the Ioniq and two years on have had no issues with low voltage in the 12v DC unit.
 

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Can anyone recommend a good maintenance charger to buy please.
Five years ago I bought one of these and have found it to be totally reliable even when used overnight monthly as part of my preventative maintenance programme. However, some reviews report that theirs failed very soon which is a puzzle. As such I am not actually recommending it and you should really research fully as I suspect that smart chargers have improved much over the last five years. Mine has been reliable though.

 

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And when the function is turned off, what way does it work ?
Have not tested this yet. Presumably it will then drain even faster since it's not receiving the small 20 minute charges each day. But it's also possible that running the timer while waiting for the next charge cycle uses up additional power. Another thing I want to test is whether flipping the master off switch in the cabin fuse panel helps extend the battery life compared to using the battery saver.

Warning, I am no electrical expert and may have this wrong!!!

If the car draws say 0.1 amps of current when locked up, that equates to about 30 watts of energy over 24 hours. If the battery saver came on for 20 mins and pumped energy back in at 14.5v / 6 amps, it would replenish the deficit (give or take charging losses). The car could (subject to traction battery capacity) sit indefinitely and always start.

I haven't seen any specs on it to know if that's what it puts out though. That output doesn't sound unreasonable as it's less than the headlights consume for example. One presumes that the output from the 12v charging circuit is more than capable of keeping up with most of the onboard 12v systems all on at the same time. If not, you are in the realms of a dynamo clad Morris Minor which with its lights and wipers on would eventually die due to a deficit of electrons. Maybe that is the issue though, maybe under heavy load, the car is relying on stored 12v energy from the battery rather than direct from the charging circuit in which case, battery depletion would potentially be a more regular occurrence. It would save on the cost of the charging circuit but is a completely naff design if that is what it is. By design, such a system would demand a larger capacity battery and one which could cope better with deeper cycling.


Of course it doesn't work in the long run if the battery is losing more each day than the saver is replenishing but surely, that is better than a traditional car which just sits there eating its 12v battery until it dies? Is that the definition of useless? Its use would seem to be to prolong the point at which you have a flat battery :unsure:
I'm an electrical engineer. To me, any system that doesn't accomplish its primary function (in this case to "save the battery" as implied by the function's name) is a design failure and therefore useless. It looks to me like they added the simplest/cheapest possible solution (a simple timer) and called it a day. Maybe it will extend the life of the battery compared to not having it at all but it will not save the battery in the end.

What you said above would be true if 20 minutes was always guaranteed to be sufficient time to fully recharge the battery from whatever was discharged in the past 24 hours. I have not measured the 12V charge/discharge rates of a resting car so maybe it's possible in some ideal scenario. It won't be the case for everyone. Temperature and condition of battery will affect how long it will require to recharge. The amount discharged in past 24 hours will also vary based on day's usage - short trips, sitting in the car parked, dashcams, etc. What if you discharged the 12V battery by accident before the next 24-hour cycle starts? What if your battery is old and can no longer hold enough charge to make it to next 24-hour charge? Using a fixed starting time and duration is flawed.

Even for a car that remains parked and unused, I can see the resting voltage slowly dropping over the course of several weeks. While the 20 minute charge cycles do work, they don't restore the voltage to the level the battery had after the previous day's charge cycle completed. As a result, you end up with a slowly decreasing starting voltage at the beginning of each days charge cycle.

Think of it this way, would it make sense for the on-board AC charger to always spend a fixed amount of time recharging the main traction battery? Completely ignoring the current SOC%? It's a very poorly engineered design.

Can't speak to other EV's but on the Chevrolet Bolt and Teslas, the charging of the 12V battery is triggered based on monitoring the voltage. When it drops to 11.8V or so (can't remember exact number), the charging will start automatically and run however long is required to get it fully charged. Only time this doesn't happen is if your main traction battery has too low SOC and the car doesn't want to risk discharging the main battery.

I have a feeling the battery gradually depletes. I had left it for some days before in it's early days with no problem.
Exactly. Comments from others that have left their cars parked and it still started don't prove anything. It depends on what state of charge the 12V battery was in before it was parked and for how long it was parked. If you start with a full 12V battery in ideal condition, maybe it's possible for it to last many weeks with the help of the 20 minute daily charges. For all we know, their 12V battery could have been deeply discharged but still high enough to start.

So far I have not been able to come up with a simple method of disabling the bonnet open microswitch that is built in to the closing mechanism.
I just stuck a flat head screwdriver in the space between the latch and switch button. Wrapped in some bungee cord to keep it secure. As long as the button stays depressed, the car will think the hood is closed.
 

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As of yesterday I have a NOCO Genius5 charger. This has a 5A charging capability that I thought would be fine for the 45Ah battery fitted in the e-Niro. I have used for the first time today and it seems to work as expected. It is safe to leave connected across the battery as when the battery is fully charged it switches into maintenance mode that will not overcharge the battery. As it is so new I am unable to comment on its long term reliability but generally the reviews seemed good. When the car is back in regular use I would expect the routine charging of the car from my PodPoint charger to keep both the high voltage battery and the12V battery charged. I would not expect to do any additional maintenance charging of the 12V battery.
 

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Whenever the car is "on" or charging the main traction battery, it is monitoring and charging the 12V battery. For most people the time spent in those two states is long enough to recharge the 12 battery. My comments above were strictly about the off/parked behavior of the automatic 12V charging.
 

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Flat 12v battery - progress report:

As some of you may recall I posted about having this problem a few days ago, and I put the car into the dealers.

Day 1: Local dealers could not work on it because they would not get paid for it; they needed to raise a ticket with Kia Technical. They observed a current drain ranging from 200ma to 700 ma variable when off.
Day 2 - 3: Weekend - no activity
Day 4 - Monday: Ticket opened. Told by Kia technical to pull fuses and to isolate the faulty circuit (duh).
Day 5 - Tuesday: All fuse tests were inconclusive because of too much variability. Needed to rule out 12v battery fault, so will detach the battery, fully charge it and monitor/measure its discharge over night.
Day 5 - Today - let's see what happens next. Wizziwiggs comments may suggest that the problem could be here (i.e. faulty 12v battery - due to poor battery saver design). Hopefully day 6 will have an outcome!

Has anyone else actually put in their vehicles over this issue?
 

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Dealers always blame dashcams.
1. My first experience with flat 12v battery was 4 months before we got dashcams installed. Back then Hyundai couldn't find the cause so they load tested the battery, charged it and returned the car.
2. Next time they blamed some calibration sensor. They said it was showing 255% charged after charging externally to 100%. Returned the car; problem appeared again 2 weeks later.
3. Then when we drove to Hyundai after having another flat battery episode they saw dashcams connected. Of course they blamed them and disconnected (even though: cameras are in parking mode and use very little power and they are wired throu circuit that cuts power if it detects battery dropped to 11.5V).
4. Then they blamed that we potentially use two key sets and they keep car awake (we don't, spare key has been rarely used only if we go on holiday and potentially loose one key)
5. Then they blamed I plugged voltmeter to OBD port (I plugged it after the battery was dead to see the voltage; sadly OBD voltmeter doesn't work when car is powered off).

And so on and on... Finally they replaced the battery and all issues gone for last 6 weeks.

Anyway, this issue should never happen (especially in EV thanks to automatic battery top up). My 13yrs old petrol Polo never had that problem :)
But as @Hitstirred said - maybe is just easier to use smart charger once a month for trouble-free car. But that is clunky solution and impractical/impossible for people living in flats.
 
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