Thank you for the beautiful video! I'm an owner of a 2018 HEV Ioniq, so it's very interesting for me. The misterious component is a latching relay, as Kevin says above in the comments. When you press the reset button the system doesn't charge the 12V battery, that can be charged only from the inverter when the system is full on. The reset button only reconnects the 12V battery after the relay had opened the circuit under a determined voltage. But under 9V the reset button wouldn't do its work anymore. Another thing is on the chemical of the 12V battery. It's a Lifepo4 with 8 cells (4s2p) with 3.2V nominal/cell. This chemical is quite secure as compared to LiPo, the chemical of the main HV battery. But of course, it isn't beautiful to see swell cells...

awesome content, thanks great video

The replacement part number for this battery is 37507G2120 Battery Module Assembly-Low VOLTAG and it is very expensive!. As therealdamon pointed out, it is likely a lifepo4 battery and not li-on as per the cell voltage readings of 3.29V which is a typical of lifepo4 cell at roughly 50% capacity. The swollen cells may be due to overcharging or even deep discharging or constant high current charging beyond its recommended amp charging of not greater than 0.5C? There is definitely limitation in max size (may be it is 50A) because of the space available. To me the extra efforts (charges) to replace the battery compare to normal 12V battery make it a design flaw., even if this integrated battery may last a bit longer than normal lead acid battery.

Crazy that the service plug doesn't split the battery voltage in half like in other cars. Not that half the voltage isn't still dangerous, but wow, I thought that was a rule.

Muchas Gracias, como dices eres el único que ha puesto algo en internet sobre la batería de 12v.

Been waiting for this for a long time

Good vídeo. I have one kona Hyundai . Hybrido 2023. Good car. The engine of the kona is very similar. = Ionic . Regars Luis of the south américa . My car (kona) . Drive the Tdh over 2800 meter of the sea. Tanks For Your videos😂

That mystery component is most likely a latching relay that's part of the run down protection. If the 12V starts getting too low due to vampire drain, the system sends the latching relay a pulse to disconnect the 12V battery from _everything_ else in the car. The 12V Battery Reset button sends it a reconnect pulse so that you can start the car, allowing the DC-DC converter to charge the 12V back up from the main battery. If you don't start the car immediately after pushing reset, it will quickly disconnect again to keep the 12V from getting so low that it becomes damaged.

In Israel, for such a battery (12 volts as part of the main high-voltage battery), the official Kia representative office gives a 2-year warranty. And the cost of this unit is crazy. They provide a 5-year warranty for the high-voltage battery, but only 2 years for its part (12 volt).

My 12v control battery died in my 2017 Niro and it is not covered by warranty, even though it's inside the "Hybrid System Assembly" diagram which is mentioned in the hybrid warranty. It was about $1.1k to fix. It's awful that Kia decided to not have this "long lasting" part be covered under a longer warranty.

top.super

We bought a 2019 Niro new and its 5 years old Jan 2024...It still has the orig 12v battery and we have had no problems, so far, quote from the Kia dealer was $376 for a new battery and labor.. but the battery still tests as brand new...We only drive 4000 miles a year and its kept in a garage...

👍🏼👍🏼👍🏼

I have a Hyundai Ioniq 2017 Hybrid and after this video, I went to my garage to see what with my 12v battery, You know what? It is swollen the same as in this video! I am disappointed - I will order a new battery... Thanks a lot for Your videos!

Hi I'm a subscriber from the Middle East. Thanks for your insights and informative content. A question please 🙏 How can I charge a single 7.2 volts battery module (6 cells, 1.2 volts each) or 1 battery block (2 modules) How much would be the input charging voltage and current ? Thanks again for your time and effort 👌

The control power was from the 12volts...control power...like a relay to initiate the full power...like a light switch

Great videos, thanks! But I don't get it - should I consider buying hyindai-kia hybrids or not? Are they reliable?

I have a Kia niro 2017 LX and it has the integrated system I feel comfortable changing it myself but my wife thinks I should have a professional change the battery. What would your suggestion be?

Do these not have the power relay like the seperate battery model,im only getting 1 click when trying to start the vehicle,car has been stood at auction and the high voltage battery has discharged,ice doesn't start

Hi I have ioniq 2018 160k miles I only noticed recently that my car suddenly jerk hard when I set off from traffic light specially when I gas the accelerate hard

I am not going to be using my car for a long time about a month I have the hybrid kona 21. Uk is a trickle charger. Solar panel a good idea. Plug it into the ODD port. ?

Hi, I should connect the 12 volt power supply of an amplifier with 35 AMP, I have a Hyundai Kona Hybrid, can you tell me the positive 12 volt and negative pole where I can connect to the 12 volt battery together with the traction battery as in your video? thanks, I'm waiting for info, bye

Hello, is it possible to discharge the main battery in disassemble to avoid electric shock? Knowing that the protector break is useless?

can you trickle charge a 2023 Kia Niro Hybrid if you leave it for months?

Thank you for your videos, I just bought a new Kia Sportage hev (in Spain), and I have seen in the owner manual that the 12v battery is integrated like the one you showed in the video. I'm wondering if the new battery pack is better or is just the same you showed, if so is there anything that I can do to keep the 12v battery in good shape? Thanks

thanks for the video. I am wondering, is Kona hybrid worth buying or do you prefer Niro / ioniq

How to check hv battery degradation level test in kia Niro hybrid

Will issue with the Integrated battery prevent car from going over 20 kmph??

When I use the stereo at high volumes, especially at night, the sound quality gets really bad. It’s like the integrated 12v battery doesn’t have enough output current to properly feed the amplifier. Years ago, to help something like this I would install a 1 farad capacitor right next to the amp to help with those high demands of dynamic music but this car is struggling even with the factory stereo. Is this because the lithium battery has lower cold cranking amps (CCA) than a lead acid battery? And what can I do to upgrade this?

Extra info on statement below: Computer read out said: "Can Bus Communication" problem, which can be almost anything, so no clue... Dealer has no idea; Hyundai Netherlands have no idea: dealer found 1 other dealer who reported similar case: recommended to renew a certain connector (do not remember which one...one of some 30 according to dealer...close to engine, possibly affected by engine heat...but one in the circuit of a (sub) can bus). After renewing said connector problem was apparently over...?? This month this connector will be renewed on mine too...trial and error method, but I have nothing else to go on...

My 2017 Niro battery died a couple days ago. The local dealer wants $10,000 to replace it. BTW, it has 423,586 miles on it. This is the first real issue.

What charger can I use to charge these batteries

superb video i have a question if you could help . i have a hyundai ionic keeps loosing communication with tcm ecm with check engine engine light . i reset this and we back to normal for afew hours to a day . any ideas where to look many thanks

Dealing with this now on top of a possible blown head gasket. They have to replace the integrated 12v battery in this video. It costs almost 600 dollars and is 1 month out for delivery. They car needs to be on to diagnose the gasket. I searched high and low just to find this video. The cost to fix the head gasket might be too high when added with this problem. I am going to ask for a loaner car for the wait. There is info on lemon warranty if the Kia/Hyundai dealership cant get your car back after a long wait. The warranty info should be with your manuals etc in the glove box.

لدي مشكله مع سوناتا 2020 في الهايبرد هل تساعدني في حل المشكاه

I wark with you where are you from way are not replay

Hey! I have an Ioniq HEV that has gone 120000 do I have an integrated 12v battery too? my 12v battery is in the trunk on the right. thankyou

Thank you Jose for your informative videos! Perhaps you can help us here in Holland: my car is playing Russian Roulette with me: Hyundai Ioniq HEV Sept 2016 First Edition, 89,000 kilometers on the clock...since last summer when she (!) must work a little, coming out of a tunnel for instance....suddenly off the cruise control, all bells and lights going off, gear shifting back to zero and stopping to complete shut down..sometimes no hard shoulder/refuge and big lorries coming up from behind...worse than a nightmare I can tell you. Car is telling me to check ESP en SCC. Waiting for her to "cool down" after some time (5 to 15 min depending on how hot she was) motor management light will switch from RED to ORANGE (possible to drive carefully) to GREEN...and all is back to normal again...apart from the driver (ME) who still has his heart beating in his throat and happy that the lorry drivers did not flatten me and my beautiful blue IONIQ....;-(( so ....PLEASE HELP if you can...

And isn't it ioniq? Don't you think?

Hi Can you help me with this code pls P1744 Transmission Engine Clutch System Performance So Hyundai ioniq 2021

Hi Jose... defently a nasty battery an poor design, You'd think they follow stacking sequence of the larger battery let air freely flow through instead of creating a compressed pan cake of trouble with heat exchangers on top that arent vented either from bottom to top.. how does that old saying go " keep em seperated" haha bafflebafflebaffle did someone say baffle ? an as for the silly service plug at the end thats just a plain junction connector with a inline fuse in the middle of the high voltage battery where i'd say a fused service plug should be. i'd be question them company themselfs an see if there in breach of any safety guidelines where there setting peoples lives at stake being of trade, customer an general public. after all if no ones speaks out they will continue doing silly things. just a thought Jose the underside of the vechile where that battery/ies resides is that insulated.... just normal reflective heat off a road can do awful damage to a vechile an its internals an if your in a hot climate like where are things would heatup quicker. eg heat from HV battery plus heat from underside of vechile affecting pan cake 12v battery that has no vent channels in the heat exchanger ( heatsink on top of battery ) plus the temperament of bus bars an relays inolved might play apart in exhausting that 12v battery.

Hey, thank you for the video! What are the symptoms of a failing 12v battery? We have a Niro and every few weeks we have to hit the 12v reset button as the car will not detect the key fob and nothing turns on.

What country are you from?