You need to book your car in with Hyundai for the recall campaign 30D042 eCall Upgrade. This was tracked to be the main culprit of the 12v battery drain issues and low battery then causing erroneous SOS calls.

 

That's great, hadn't seen anything about that. Does that involve a replacement SOS module or just a software update?

 

It's a control logic (software) improvement. You used to be able to look-up your VIN on the hyundai.de website for any outstanding recalls but that seems to have stopped working now. See: https://www.ioniqforum.com/threads/campaign-on-38kwh-ecall-system-battery-drain.46440/

 

Actually found a new URL for it: https://www.hyundai.com/de/de/servi...m/de/de/service/serviceleistungen/uebersicht/rueckrufe-und-serviceaktionen.html

Just pop in your VIN and it'll tell you what, if anything is outstanding.

 

I've seen this once a few years back, but put in down to a failing 12v battery. Since fitting a new battery It's been ok and the SOS red light has remained off.

 

There doesn't seem to be anything wrong with the 12V. This is only the 2nd time it's happened in nearly 5 years so looks like some weird glitch.

 

Happened 2x to me on my Hybrid IONIQ 21
Annoying but not critical as once you know how to open the door with the mechanical key and then push the 12V reset switch, all falls back into place.
However would be great to know how to cancel that SOS call and how to cancel the 12v drainage resulting. Maybe hitting the rest switch immediately after turning off the engine? Need to try!

 

The EV doesn't have the luxury of that 12V reset, so it's a jump start only for me!
Although I think maybe an 8Amp or larger battery charger has enough oomph to start the EV at least. A 4 or 5 Amp charger also seems to be enough as long as you connect it for 10 minutes or so then start the car
I've not tried reset of the head unit but apparently it doesn't work. It's more likely that disconnecting the 12V for 5 minutes or so should do it based on the fact that the SOS unit does seem to reset itself once the battery is completely flat.
But yes at least we know that if the red light stays on then there is a battery drain so can expect a flat battery.

 

Out of interest does anyone know how many amps are required to start the Ioniqs systems?
I've read that the contactor requires only 1 or 2 Amps.
Though considering the car seems to use about 200W when powered on, I would estimate that 200/12 = c16Amps.
So maybe a 10Amp car charger wouldn't be enough unless it was left charging the 12V battery a few minutes.
I've just bought a very cheap jump starter pack off eBay.
The specs claim it is a 20000mAh pack though I very much doubt that. Think it is closer to 3000mAh which I've estimated whilst charging it up (it's taken about 15Wh to fully charge). But hopefully should be sufficient next time I get a flat battery, as long as it can supply enough power to fire up the systems for 1 second or so.

 

Out of interest does anyone know how many amps are required to start the Ioniqs systems?
I've just bought a very cheap jump starter pack off eBay.
The specs claim it is a 20000mAh pack though I very much doubt that.

I was surprised last year when my at least 5-year-old generic lithium jump starter pack with only 3 out of 4 led’s lit started a petrol Mini with a completely flat battery. With an EV only a few relays plus the main battery contactors need to be switched, with no engine to crank over I don’t think it needs that many amps.