[MaineNiro]

New member here. I have a 2019 PHEV, production date 11/18 that I bought totaled from an auction in 2020 with 5,000 miles on it. It had minor front damage to the front passenger-side quarter. No warranties/recourse, etc. I have the car on the road under a rebuilt title now and my wife had put over 10,000 miles on it in the past two years, with no real issues. There is an engine cylinder 3 (lean) misfire code that comes and goes, which based on TSB 212, indicated a new cylinder head may be needed. I've done some playing around to see if I could eliminate that misfire with periodic success, but this car doesn't really merit a new head at this time (that I would have to buy and install) based on how smoothly it runs. I work in a mechanical building trade for a living and wrenching on cars is a hobby. I bought this PHEV because I was looking to get into working/understanding electrified cars and get my wife something that was a little newer. She has a 5 mile commute to work so this car is perfect. My only complaint is that the engineering to make the AC a heat pump is relatively minor, so it doesn't make sense to need to use the ICE just for cabin heat.

Right now I'm having a battery drain issue that has me (temporarily, I hope) stumped. Last week, on Thursday, my wife went to start the car (she leaves it unlocked - we live in rural Maine) and nothing happened. I figured out pretty quickly that the 12V lead acid battery in the trunk was dead (about 5.5volts). I sent her on her way in the GMC pickup truck (which gets 10mpg, ugh) and put the charger on that battery. I did some reading and found here that the 12V battery is generally pretty short-lived. I also know that when I bought this car, it had sat through most of a winter at the auction yard with an almost dead battery. The day I picked up the car it started on its own - the next day when I went to drive it off the trailer it wouldn't start, so I figured out pretty quickly how that 12V battery operates (and that you could "jump start" this car with a lawnmower battery). So I believed that the most likely issue was the battery needing replacement.

I went to Autozone to buy a battery. I find a lot of their parts to be junk, but their Duralast batteries have been good to me. FYI nothing shows up in their computer for the PHEV 12v batteries - the battery size is a T4/ Group 99R. Autozone likes to tie battery searches to a specific car, so if you have them pick a Niro EV from the "Kia Trucks" list the 12V battery you need will come up.

I topped up the battery on Friday and installed it Friday night. We drove the car around all weekend three or four short trips, thought nothing of it (had family in town, had it in the back of my mind to check voltage but didn't remember to do it). I had a spare topped up 12V battery in the trunk in case I needed an emergency start, but didn't need it. Monday (yesterday) morning, she goes to start the car and nothing again. I check the voltage, and it's down to 5.5V again.

Now I know I have a draw or failure to charge issue. I charged the battery again yesterday and did some basic tests - headlights on, yep charging. Checked every mini fuse with voltage drop tests, pulled and tested every cartridge fuse. No apparent issues there. I was going to start looking at the multi-fuses but didn't get that far.

I got two new multimeters last night to do some current testing. None of the meters I had on hand took reliable DC current readings (anymore). I let the car sit in sleep mode (latches locked, one hour rest) and tested the draw. Under 50mA, no parasitic draw happening, which rules out the rear door latches found in TSB 163 for earlier models than mine.

I'm still stumped and gave up after two days of playing around. I put a battery kill switch on the 12V battery and went over the new routine with my wife - drive with headlights on, charge car (we do 120V charging), disconnect charge cord and kill the battery switch overnight. The only pain in the butt is leaning over the rear seat in the morning to switch the 12V battery back on, but we can deal with that for now.

I've ordered a bluetooth battery voltage monitor and a cigarette lighter USB/volt meter so I can see when the voltage draw is occurring. I did read on the Ioniq forum that one member there had an infotainment center that caused a similar huge draw, but pulling the dash apart is going to be the last thing I want to do unless I have to. I don't know how much the draw is, but to toast a fully charged battery it has to be at least 1Ah per hour so I'm looking for a sizeable draw.

I'll keep this post updated when I figure out more.

 

[Techy]

I agree that the draw should be close to 1A or at least .5A to drain that quickly. I don't understand why you only get a reading of 50mA.
I hope you persevere and solve soon. At least you don't throw up your hands and say "can't find a problem", like too many Kia dealers will do.

 

[FlNiro]

One thing comes to mind but it's just a shot in the dark. Did you change where you leave the key fob overnight? In the past I read that if you leave the key fob too close to the car it keeps communicating with the car and that causes battery drain but I believe that takes several days???? Just thought I'd mention that.

 

[MaineNiro]

The problem is that the draw is only happening when I'm not watching it. Hopefully the battery monitor will spit out some useful data so I can pinpoint the issue to weather or some specific time of the day. Intermittent problems stink.

The key fob has been in the same place. We have been mindful to keep those far away from the car so I don't wake the sleeping giant. I had a similar issue with a VW TDI a few years ago.

The only regular cause in these cars that keeps coming up seems to be the rear door switch one - water gets in and keeps the ECU or some other module alive. There is a cut off of manufacturing dates in the TSB and my car comes after them, not that those dates are 100% reliable.

There was a blip of a power outage last week - that could have come with a power surge. In my real job I have seen many toasted circuit boards from power surges. Strange things happen when capacitors and fuses explode on these boards. At some point I will try to check all the relays and the multifuses.

The new battery was almost $200. I really don't want to keep drawing this thing down to early-death-by-sulfate SOC.

 

[Techy]

You got a real good handle on the situation.
Use a smart battery charger once per month and that should solve your "early death by sulfate"...still a pain to have to do that.

 

[MaineNiro]

Thanks. I guess it's a question, once (if?) operation gets back to normal and not dying every day or two. Otherwise it's going to have to get topped up much more frequently, unfortunately.

 

[yticolev]

Mentioned a lot on the Ioniq forum is a 12 volt monitor that installs on the battery terminals that produces graphs of voltage. While it is not going to identify a specific culprit, it looks like it can be a lot of help. One feature of the PHEV (and BEV) is that the 12 volt battery charges intermittently from the traction battery via a DC/DC converter. The trigger is low voltage, and that can even happen when car is off (search options for Battery Saver Plus - on some models it may be enabled without user option). So a 12 volt monitor can document when this happens (data supplied via a phone app) and identify the trigger voltage. Kind of a pain if everything dealer is out of pocket, but some updates affect the trigger voltage, and how long the charge cycle lasts.

All kinds of interesting things seem to happen to users of the battery monitoring system on the Ioniq forum. But the deal is that lead acid batteries have a very long history of reliability with alternators supplying constant charging voltage with batteries lasting up to 5 years (my motorcycle battery lasted 8 years before replacing recently). But all electrified vehicle forums have endless reports/complaints of early lead acid battery failure. No doubt that is a problem with any modern car with an out of range vampire current running door locks and alarms et cetera, or not driven regularly. But cars designed with intermittent charging (which in recent years includes some ICE cars like my sister's 2013 Subaru) are especially problematic. Voltage drops creates sulphation, which causes battery failure. Yes, you can maintain them with smart trickle chargers (at least once a month as Techy said) but it is a hassle. You can make it less so by attaching leads to your battery that simply plug into the charger, but still. That's what I do with my motorcycle battery in the winter by the way.

So good luck with finding the current drain! That has to be solved, but when it is, I'd use a smart trickle charger to maintain battery health. Super happy that my Niro HEV has no issues as it doesn't have a lead acid battery at all.

 

[MaineNiro]

Thank you. I did order one of those bluetooth battery monitors after reading a bunch of the Ioniq posts. One owner posted a graph. It appears that the charge cycle is based on time, not SOC, and that the top up time is some preset length. That would explain why a battery can drain so quickly.

With VWs a shade-tree mechanic can change a lot of programming options with some affordable aftermarket software and no real coding knowledge (which I have none). I don't own the software, but I have a friend that I can borrow it from. When the OEM battery died in my TDI you need to tell the ECU when you're replacing the battery, what the amp hours of the new battery are and what the chemistry of the new battery is. It then fashions a charging profile/program that should maximize the life of that battery (in theory).

I'm now realizing that this is not really a Kia thing, as far as user-programing. It's too bad because these types of programming changes could be easily modified with the right set up - like changing the charging cycle. I'd love to be able to do things like turn the 4G modem off. It would be nice if, instead of spending so much money shoving technology into cars that many people don't need or want, they could do something basic like battery voltage monitoring. I've never once wondered if lane-assist is going to work. I have been stranded many times by dead batteries. The car has all the technology it needs to call or text you when the battery voltage drops. Where is that programming?

 

[MaineNiro]

The local Kia dealership I worked with to get parts was very friendly. Maine is a very rural state and a small state, population wise. Our dealers up here tend to be mindful of the small market and are not that unreasonable to work with. I bought the car from an auction and the Kia dealer let me buy needed parts to get a rebuilt title under the shop rate (15% off) it sells to local garages at. I could have tried to figure out every part and ordered from the internet and saved some nominal amount, but that's not wise with some manufacturers. Instead I was able to put a decent list together, went and saw them and worked out the differences based on them putting my VIN into their programs.

If I believed that getting an update to the firmware would solve the issue, I would happily schedule service there and pay for it. They probably wouldn't charge much more than a half hour of service time, knowing this place.

 

[91cavgt]

With me HEV, I found that if you kept the headlights on all the time, it forced the DC to DC converter to constantly charge, just like what an alternator would do. I kept the headlights on in my car due to the subwoofer amplifier. If the voltage was low, it could fry the amp and I didn’t want that to happen. With it pulling up to 100 amps of current, that voltage would drop VERY fast with the headlights off.

 

[MaineNiro]

I got the battery monitor and put it in yesterday. The car had been sitting all night and most of the day with the 12V battery switched off. The car didn't go anywhere until 7pm. It looks like just opening a door to put something in or taking it out doesn't really take the ECU out of sleep. I had battery saver on. Right around 5pm the car topped up the battery. The battery slowly equalized over the next hour and then something strange happened. The ECU seemingly woke from sleep and started to draw good power, which continued to draw slowly over the next hour until I woke the car up to take it for a 30 mile drive. I think the monitor will be helpful, if I can figure out a pattern and investigate which component specifically is sapping battery power. Also, if this issue is tied to battery saver, well I can certainly live without that.

 

[MaineNiro]

This is the rig. Not the prettiest. To quote Red Green - "now this is only temporary...unless it works."

 

[Techy]

This is the rig. Not the prettiest. To quote Red Green - "now this is only temporary...unless it works."

I admire your ingenuity and perseverance but all of what you are doing should not be necessary and the majority of Kia drivers will not put up with the hassle.
@91cavgt is correct when saying that turning the headlights on all the time causes the 12V battery to be "charged" constantly. Why the subwoofer, which draws many more amps, would not cause the 12V battery to be "charged" in similar fashion is again, a Kia/Hyundai head shaker!!

 

[MaineNiro]

I'm not going to speak for the overall reliability of the Niro/Kona/Ioniq in general because that's way over my head. All my vehicles prior to the Niro and a 2015 VW Golf TDI have been on on platforms that have been around for two decades or more. These are my first two forays into modern electronic-bloated vehicles.

No one wants to put up with mystery hassles if they buy a new car for new car prices. My ideal ICE car is pre-vacuum tube era with a carburetor. Simple to work on and troubleshoot. I bought this straight from a car auction at totaled price. If I didn't win the bid this particular car most likely would have been stripped for parts or shipped overseas. Auction cars only are eligible for safety recall repairs at no cost and in a lot of states they are not legally rebuildable. It's buyer beware with these types of cars - no recourse if it's a lemon. And you never know what can go wrong, mechanically or electronically when a car takes an impact. I had to have a body shop re-bend the front end of the unibody "frame" back 1.5" to 2" that it got whacked out of alignment.

This car is basically stuck in Maine for its whole life - most states won't accept another state's rebuilt titles. For what I have into it, the day I get too frustrated with it I could strip it and get more in parts than I paid for it. Just figured I'd do my part to throw out there what I am learning as I go. This is my first problem in 2 years. I can live with that.

 

[Techy]

I'm not going to speak for the overall reliability of the Niro/Kona/Ioniq in general because that's way over my head. All my vehicles prior to the Niro and a 2015 VW Golf TDI have been on on platforms that have been around for two decades or more. These are my first two forays into modern electronic-bloated vehicles.

No one wants to put up with mystery hassles if they buy a new car for new car prices. My ideal ICE car is pre-vacuum tube era with a carburetor. Simple to work on and troubleshoot. I bought this straight from a car auction at totaled price. If I didn't win the bid this particular car most likely would have been stripped for parts or shipped overseas. Auction cars only are eligible for safety recall repairs at no cost and in a lot of states they are not legally rebuildable. It's buyer beware with these types of cars - no recourse if it's a lemon. And you never know what can go wrong, mechanically or electronically when a car takes an impact. I had to have a body shop re-bend the front end of the unibody "frame" back 1.5" to 2" that it got whacked out of alignment.

This car is basically stuck in Maine for its whole life - most states won't accept another state's rebuilt titles. For what I have into it, the day I get too frustrated with it I could strip it and get more in parts than I paid for it. Just figured I'd do my part to throw out there what I am learning as I go. This is my first problem in 2 years. I can live with that.

I understand that you made the purchase knowing full well anything could happen.
I hear you when you mention carb area cars - totally my fav as well as they were "simple to work on and troubleshoot" as you say.
Not sure how much of this forum you have navigated through but you might be interested in the following thread:

2022 PHEV Battery Drain

I have a 2022 Kia Niro PHEV and everything was great until a couple of weeks ago. The car was dead. We had it jump started and it seemed fine. The next morning, it was dead again. I took it to the dealer and they ran diagnostics on it (twice) and said there were no problems with the battery...

www.kianiroforum.com

 

[MaineNiro]

I had not seen the most recent part of that thread - which indicated a faulty BCM. Good to know. I'm suspecting an intermittent failure in one module. I've only seen one small blip on the battery monitor since it was installed, but it was concerning.

I have not completely ruled out that the new battery was severely undercharged when I installed (but it seems unlikely - I'd put this scenario at 10% probability) it and that the initial driving around the first weekend was done under unenlightened conditions where we were not aware that headlights were needed to keep the battery charging. I think we did not plug in the car at all during these two days either.

My wife typically has a schedule that is good for charging, now knowing how the vehicle operates. On days when she works in the winter, she leaves for work when it's dark and comes home when it's dark out. On days she's not working she makes short forays into town and is in the habit of coming home and continually charging the car. Even so, the car has sat for long periods over the past two years and in the summer many small trips are taken with no issue. So I'm inclined to believe that there is a problem.

I don't know how good Kia's diagnostic tools are, or at least what's available to US dealers. If I can't figure out the problem easily, it would be nice to be able to pin it down to a specific time and see if a Kia dealer can pull data out of the car for that period to figure out what module was operating. Right now I'm just constantly checking the monitor and hoping to find the car in drain mode.

 

[Techy]

I had not seen the most recent part of that thread - which indicated a faulty BCM. Good to know. I'm suspecting an intermittent failure in one module. I've only seen one small blip on the battery monitor since it was installed, but it was concerning.

I have not completely ruled out that the new battery was severely undercharged when I installed (but it seems unlikely - I'd put this scenario at 10% probability) it and that the initial driving around the first weekend was done under unenlightened conditions where we were not aware that headlights were needed to keep the battery charging. I think we did not plug in the car at all during these two days either.

My wife typically has a schedule that is good for charging, now knowing how the vehicle operates. On days when she works in the winter, she leaves for work when it's dark and comes home when it's dark out. On days she's not working she makes short forays into town and is in the habit of coming home and continually charging the car. Even so, the car has sat for long periods over the past two years and in the summer many small trips are taken with no issue. So I'm inclined to believe that there is a problem.

I don't know how good Kia's diagnostic tools are, or at least what's available to US dealers. If I can't figure out the problem easily, it would be nice to be able to pin it down to a specific time and see if a Kia dealer can pull data out of the car for that period to figure out what module was operating. Right now I'm just constantly checking the monitor and hoping to find the car in drain mode.

Did you charge the new battery before installation?
I always put a smart trickle charger on a new battery before I install it.
I don't think that is your problem but again, you do seem to be on the right trail. Looking forward to hearing the drain source, once you have found it.

 

[MaineNiro]

I did. Would you believe that I also don't own a trickle charger? Just one of these old transformer chargers that's older than me. I think I had it on there for an hour. I charge by the needle. It did seem like it was initially charging at a high rate - over 3A. A fully charged 12V battery will pull under 1A on this charger. 6A+ would be completely dead.

 

[Techy]

I did. Would you believe that I also don't own a trickle charger? Just one of these old transformer chargers that's older than me. I think I had it on there for an hour. I charge by the needle. It did seem like it was initially charging at a high rate - over 3A. A fully charged 12V battery will pull under 1A on this charger. 6A+ would be completely dead.

I love my Battery Tender .75A smart chargers for my motorcycles. Leave plugged in all winter and never worry about "no start" next Spring. Also don't have to worry about overcharging either.

 

[MaineNiro]

I have overcharged a battery or two before I became a smarter charger. Now I use strategically placed sticky notes and google calendar to avoid that problem. I usually have 3 or 4 batteries to keep topped up over the winter. One weekend day a month the charger hops from battery to battery. I did have a trickle charger I was given that ended up dying, so I'm not completely anti-modern technology! I just have a real hard time determining that there is a need to buy a new tool when I have an old one that still works.