I have a 2019 (USA) Kona and after a long drive (380 miles combined) the next day got a "12v battery voltage low. Stop safely" message on the dash. Next day completely dead. I trickle charged battery and drive to the dealer. They replaced the battery, but I asked for the old battery and bench tested at 2 auto parts store and it tested GOOD 3 times. And now the console screen is cycling on and off, on and off. Should I ask the dealer to see what the "codes" are saying? Could updating the battery management system software maybe fix this? At any rate, I guess I need to join the ranks and buy on a small jump started battery pack as an insurance policy. (not sure if I placing this question in the right place, being unfamiliar with forum norms).
Dead Kona EV!
XtsKonaTrooper
Well-Known Member
Thanks for reminding me to put my battery booster pack back in the Kona...imo the problem with kona charging system it can kept up on especially long drives and definitely in cold weather. When u go start the EV and if the 12v is not where it needs to be, it will either be completely dead or errors. Plug in a booster for a few seconds, in my experience it will start back up and good to go. However charge the 12v asap.
If you are talking about the centrally located infotainment screen, I would try to reset it (little hole by the volume button IIRC- push with paperclip end for a few seconds with the car powered on). It may have been on when the 12V battery was disconnected, and now it went into "stupid mode". If that doesn't solve it, take back to dealer.
I believe you have identified the problem (or at least one of them) that causes the 12v battery to die. I seem to recall in another forum that the climate controls do not always turn off when the light shows OFF. So whatever causes the climate control to not shut down correctly when the car is turned off, will likely cause a substantial drain on the 12v battery. If the automatic "top up" from the big battery doesn't keep up with the drain, the 12v battery will die.
I recently had my 12v battery replaced on my 2021 Kona under warranty. The service person said he had found that someone with an OBD bluetooth dongle connected all the time, killed the 12v battery because it keeps polling the various systems on the car and hence kept them alive instead of going to sleep. I have since removed my dongle, but since I had it connected for most of the two years that I've owned the car, I doubt that this is really the cause.
When my defective 12v battery was down to something like 7volts, I could hear a sound like a contactor opening and closing. At that point, my trickle charger couldn't charge the battery. The only way to charge it was to disconnect it from the car and then charge it. But it wouldn't hold the charge and was replaced.
I recently had my 12v battery replaced on my 2021 Kona under warranty. The service person said he had found that someone with an OBD bluetooth dongle connected all the time, killed the 12v battery because it keeps polling the various systems on the car and hence kept them alive instead of going to sleep. I have since removed my dongle, but since I had it connected for most of the two years that I've owned the car, I doubt that this is really the cause.
When my defective 12v battery was down to something like 7volts, I could hear a sound like a contactor opening and closing. At that point, my trickle charger couldn't charge the battery. The only way to charge it was to disconnect it from the car and then charge it. But it wouldn't hold the charge and was replaced.
kalel681
Member
I've had Cortana (2022 Kona Ultimate 16000km) die on me three times. After reading this and the other threads I can predict when it's going to happen. On latest Canadian software. If HV battery is under 40%, 12V will die in just over 24h.
Dropped the Kona off at the dealer Sunday at 33% for appointment Tuesday am. Also getting gear reduction fluid changed per these forums.
Low-and-behold, this morning when they tried to get the car, it was dead. Just to make sure they couldn't say I was wrong. Tech asked to keep it for another day to try and replicate it. Let's see what they say tomorrow.
Dropped the Kona off at the dealer Sunday at 33% for appointment Tuesday am. Also getting gear reduction fluid changed per these forums.
Low-and-behold, this morning when they tried to get the car, it was dead. Just to make sure they couldn't say I was wrong. Tech asked to keep it for another day to try and replicate it. Let's see what they say tomorrow.
KiwiME
Well-Known Member
Did they complete the gear oil change and were there any comments about that?
I was at the dealer today to get the annual safety inspection our government requires and was told I have three outstanding TSBs. One is yet another "VCULDC Control Logic Improvement" update (which includes 12V battery charging) and the other is the kickoff for the traction battery replacement.
Do you have a BM2 to monitor the 12V battery? It's worth its weight in gold for identifying 12V battery issues.
I was at the dealer today to get the annual safety inspection our government requires and was told I have three outstanding TSBs. One is yet another "VCULDC Control Logic Improvement" update (which includes 12V battery charging) and the other is the kickoff for the traction battery replacement.
Do you have a BM2 to monitor the 12V battery? It's worth its weight in gold for identifying 12V battery issues.
kalel681
Member
They completed the change. The tech said that the fluid was grayish, but that it was normally almost that color new. Maybe they've fixed the issue on the 2022+ models?
I don't have a BM2, but I have an ODBII dongle as well as the sensors setup through Home Assistant. Should give me ample info.
KiwiME
Well-Known Member
Same description for what hair is left on my head, used to be "clear brown" (new) however now "grayish" (not as new)
Except magnets don't fix it
Couple of questions....
(1) what was the xisting SOC of the main battery (HV pack)
(2) was the vehicle plugged in and charging
(3) what was the ambient temperature
Relative quotes from this Hyundai patent :
" the LDC controller may set the LDC output voltage and the sub-battery charging time (or LDC operation time charging the sub-battery) according to the SOH of the sub-battery (S14), and then may determine whether or not the SOC of a main battery is sufficient to charge the sub-battery"
"When determining whether or not the sub-battery needs to be replaced, the charging time and the SOH of the sub-battery and the SOC consumption of the main battery due to the periodic charging of the sub-battery may be used."
" since there are many related parameters, such as electronic loads of a vehicle, charging/discharging frequency of the sub-battery, and temperature of the sub-battery"
Regarding that last quote, I have experienced a dead battery (4.7V) once, on my 2019 MY when a hung Bluelink command queried overnite. It was a command to reset the service interval...of all things. I have not enabled on my 21 MY, and have had no 12V issues.
There has been another report of an EVSE not communicating with the on board charging protocol, and killing the accessory battery as well.
This flow chart does give an indication of a "minimum" SOC of the HV pack (above 25%) required to initiate the charge cycle:
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kalel681
Member
SOC was at 22%, but, I've left it that low before and never had any issues.
Was not plugged in or charging.
Ambient was approx 9deg C
According to the flow chart, the recharge cycle will not operate
Manually recharge the 12V battery using a battery charger, enough to start vehicle (it won't take long probably 10 minutes). Start vehicle then leave in utility mode for ~2-3 hours, lastly recharge main pack above 30% minimum.
Keep an eye out for the yellow light on the Hyundai badge in the front, it should come on ~.5 hours after a drive, again at ~2 hours later, then resort to 4 hour recharge cycles. Better yet install a BM2 monitor if you don't want to monitor the indicator light.
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KiwiME
Well-Known Member
This update finally showed up this week and I'm booked for it in 2 weeks. I can hardly wait to see the differences because I'm certainly seeing wider 12V battery voltage excursions now that it's 4 years old and struggling more.
One trick I've acquired is to place the car in Utility Mode when I park it in the dealer's microscopic service lot to ensure that it's in the highest possible SoC when they leave it for hours with the hood open. I mentioned that it was in this mode to the service admin when I checked it in and of course she looked at me like I was from Mars.
I read on another part of this forum that the Kona Electric uses a calcium lead-acid chemistry.
This means it requires a higher charge voltage (up to 16V for a short time) to get maximum life.
Also, the BMS on a LFP battery low voltage disconnects into sleep mode when any cell voltage gets too low.
This makes jump starting more tricky. You have to remove all loads and let it rest for a fair amount of time before jumping the battery (still disconnected from the car) to wake it up. A current limit device might be needed.
EVatLast
Active Member
It appears our 12v battery has died, 2019 Ultimate Dec 2018 build date. We went shopping yesterday and after our first stop it came up with a "12v battery error, pull over asap", but the error cleared itself and we carried on to the next stop. There the battery completely died, should have went straight to a battery store. We hooked up our little lithium jump battery and that started the car but it only lasted a few minutes and then that died as well.
The Hyundai dealer is 20kms away but Canadian Tire was just across the street so over I went only to find that the clerk needs to see battery to try and match it, they don't have an actual listing for the KONA EV. Removed the battery, took it to CT only to be told by a different clerk" we don't stock that size", expletive deleted!
Up the street a few blocks is a stored called All Battery so we called them and more or less got the same story of having to see the battery to try and match it, thought about it for a few minutes and called a cab. As luck would have it they had one battery the same footprint but a 3/4 inch taller so I grabbed it and ran as the cab was waiting for us. The extra height makes it a tight fit but it works, the only thing is the cap for the negative terminal doesn't fit the new battery.The store is going to charge and test the old battery to make sure it's the battery and not the car charging system that's at fault but as of now there are no errors and car seems fine.
The new battery is a :
Polar Automotive 26R-550SW
600CA 550CCA 90R/C
The car does it's regular 4 hour top up routine and the problem of the 12v dying hasn't been a problem for a long time.
My big questions here are, why didn't we get any pre-warning that the battery was duff if it is duff? If not duff, why did the battery not get charged on the 40 min drive before this occurred? I'd hate for this to have happened in the middle of nowhere....
The Hyundai dealer is 20kms away but Canadian Tire was just across the street so over I went only to find that the clerk needs to see battery to try and match it, they don't have an actual listing for the KONA EV. Removed the battery, took it to CT only to be told by a different clerk" we don't stock that size", expletive deleted!
Up the street a few blocks is a stored called All Battery so we called them and more or less got the same story of having to see the battery to try and match it, thought about it for a few minutes and called a cab. As luck would have it they had one battery the same footprint but a 3/4 inch taller so I grabbed it and ran as the cab was waiting for us. The extra height makes it a tight fit but it works, the only thing is the cap for the negative terminal doesn't fit the new battery.The store is going to charge and test the old battery to make sure it's the battery and not the car charging system that's at fault but as of now there are no errors and car seems fine.The new battery is a :
Polar Automotive 26R-550SW
600CA 550CCA 90R/C
The car does it's regular 4 hour top up routine and the problem of the 12v dying hasn't been a problem for a long time.
My big questions here are, why didn't we get any pre-warning that the battery was duff if it is duff? If not duff, why did the battery not get charged on the 40 min drive before this occurred? I'd hate for this to have happened in the middle of nowhere....
