12V battery

The last previous drive was on the 18th. Between then and the 24th, there were times it charged every four hours or so, as in the graph at the top, and times when it charged about every 24 hours.

It has still not charged since the 24th, and is at 12.52v this morning.

Seems to me that the voltage has dropped faster in the past. I wonder if the car decided to go into a low activity state, or I put it into one accidentally, and the lack of charging is just responding to the lack of need to charge. I suppose I could ping it by checking status with the app, but I'm curious to see what will happen like this. Although at this rate it could be much longer than I want to avoid using the car for.

 

That's what I'm thinking and that's based on the past observation that a short drive does not disturb the aux battery saver's existing time schedule, while a longer drive does, perhaps longer than approx 30 min.
But it's odd that the 4-hour charge events have not raised the voltage level as would be expected. Is this the same aux battery that has suffer a number of deep discharges or has it been replaced?

 

You made it nervous with all those questions, so it charged today.



Yes, this battery has been fully discharged two or three times, plus the times I caught it in the act, once around 11.8v and the other time well below 9v. But it held up fine for the week when the Kona didn't charge it. When it has trouble keeping a charge is when it's charged close to 13v.

Does everyone see that pattern of charging every 4 hours, or is it just my problem car?

 

Well, 4 hours is the expected post-BMS-update behaviour but it seems you're the first to report on longer periods of being parked. I don't have the update yet.

 

My Kona EV car did not have any power two days ago. After reading comments here we got a tow truck by calling Hyundai road side assistance and they jump started the car. Everything came back to normal but I took it to the dealer to see what could be the issue. They told me there’s nothing wrong with the car, which is ridiculous, the car just doesn’t die all the sudden if there are no issues. I called Hyundai and elevated my complain, waiting to see what they come up with.
This car is only a year old, no way it should have this kind of issues. Also I do not feel safe driving it around now, thinking this might happen again.
I was told I probably left a light on. The lights are LED, that should not be enough to kill the car overnight (it was driving fine the day before), and when the car started nothing was on inside. Also, no explanation why the backup maintenance mode didn’t come on to recharge the battery.
Very disappointed that they would basically give me the car back without any explanation on how to prevent this from happening again. I’m starting to think it was a bad decision buying from Hyundai.

 

2 more complaints of dead aux batteries on Facebook today, both have the BMS update.

 

Dead battery also. BMS update done two weeks ago!

 

Hyundai should include a compact battery jumper pack along with the tire inflator kit.

It's not that bad. The first time it happened, I bought a compact battery jumper pack. It takes about two minutes to pop the hood, clip it on and start the car. Since there's no ICE to start, it only takes about 30A so the smallest jumper pack should work.

It's a nuisance, and doesn't speak well for Hyundai engineering or support. But I don't worry about being stranded.

 

My 12 volt battery died at 8 months a year ago, long before the software update. Much to my surprise the group responded to my consternation with a pretty much unanimous "no duh". Apparently EVs have been eating batteries for breakfast since forever. In my case they replaced the master control unit (I could have that wrong). My point is, blaming the dead 12 volts on the update might well be a mistake.

 

I think this problem is unique to Hyundai EVs. Maybe Kia?

And yes, it's well known that it's been around for a long time. The only point about the BMS update was our now forlorn hope that it would fix the problem.

 

All the folks who chimed in had histories with different EVs. Hyundai didn't even have them on the market at the time.

 

Tesla’s eat 12 volt batteries as well.

 

I believe leafs have also been troubled with this. The problem I see is that lead acid batteries are not optimized for being chronically undercharged as in many EVs. If you do it enough the plates start to sulfate and you just need one cell to start failing and it will eventually bring all of them down. I suspect the batteries that are going flat will just get worse regardless of the BMS update as the damage has already been done. I suppose a guy could look at AGM or lithium iron phosphate batteries that are cold charge rated as a replacement. These technologies seem more more tolerant of deeper discharge cycles. The problem is the BMS will still have a charge profile geared for lead acid.

 

I wasn't aware of this:"Apparently EVs have been eating batteries for breakfast since forever" My experience is different; my 2015 Kia Soul EV (new Feb 2015). It still has the original 12V battery, which worried me, so I installed a Battery Monitor BM2 and it shows a still good battery at 12.7 V or better. I'm getting a Battery monitor to put on my Kona 12V Battery.

 

Leafs have been and the general consensus for it was to get an AGM battery, so I think this is a valid suggestion.

 

It's not the 12v battery - at least not in my case. I have seen the BMS get into a loop where it sucks the 12v battery down over a few hours. For me it seems to happen when the EVSE is plugged in, so I just leave it unplugged except when I occasionally charge.

I'm still holed up, but am comfortable living with it until things get back to where I can go have a chat with the service manager and tech. It will probably take replacing some system on the car.

 

I just installed the battery monitor that was recommended earlier in this thread.

When I first hooked it up, the icon on the app showed a red color, "low" and 12.65 volts.

About an hour later, I checked the app and the icon is blue, "battery okay", 87% and 12.79 volts.

I'll post if/when some 12 volt drama happens over the next 10 years...

 

The service did not find anything wrong with the battery or the car, that’s why I suspect it has to be a software issue. They just gave me the car back without any explanation why this happened. Still waiting to hear from Hyundai.

 

UPDATE: I received a call from Hyundai today regarding the car and they told me that if the service center did not find any issues with my car they do not have any further explanation or anything they can do. They could not even tell me if the tests the dealer run on the car were correct since "they rely in the service centers for these issues" so the company can not do anything. Hyundai offered to discuss the problem with the service center and the technician gave me a call and explained that my car has no issues and that I have to drive the car at least once a week for the "hybrid battery" to charge and that they run a full test in the battery and that the battery and alternators are fine. Several issues here: electric cars do not charge 12v batteries by driving and EVs do not have alternators. So now I feel less reassured than before about my car, since the service person did not even know how an electric car works. Also the service did not know the Kona EV has an Aux. Battery saver function and they told me that did not exist.
I guess the solution here is to find a competent service that knows about electric cars. But not reassuring that Hyundai is not willing at all to deal with complains, not a very good costumer experience so far.

 

My car and its 12 volt battery heartbeat:



This is a typical pattern when the car just sits in the garage, undisturbed.