Using the OBDC dongle

If you keep the drive battery above 20% the 12V will be charged. Yes, I keep mine plugged in but I don't let my drive battery get below 20% overnight.

dundeeyank said:

If you keep the drive battery above 20% the 12V will be charged. Yes, I keep mine plugged in but I don't let my drive battery get below 20% overnight.

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Thank you. I keep the battery usually above 50% unless I am driving a couple of hours or so.

The one I have says auto off so it won't drain the battery. But I usually just plug it in now and then when I want to check something and don't leave it in all the time.

Also a note, Hyundai has put out a TSB saying using dongles like code readers or insurance discount trackers can cause problem with vehicle electronic communications and in these cases are to check for dongles or ask the owner if they had been using one but removed it before bringing the car in. The chance of having issues is probably low, but if you start having codes or errors showing up remove it for a while and see if that helps.

tsekhar said:

For all the folks who use a OBDC dongle...do you leave the device plugged in all the time or only when you need it? My concern is that if you leave it plugged in all the time, is it likely to drain the 12v battery?

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Remove it, unless it has the auto-off mode. All other dongles will flatten the 12v battery.

Cycling the 12v battery via the automatic top-up should be avoided, it degrades the lead acid battery chemistry.

GDS official diagnostic software can retrieve detailed 12V battery data 30 days back, including battery drain caused by any aftermarket devices:

Also to note, unless you have a dongle that has a physical connect button then anyone can connect to it.

I unplug mine when not in use.

mondotang said:

Also to note, unless you have a dongle that has a physical connect button then anyone can connect to it.

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Yep, I installed a switch but the manufacturer of the switch was not thinking it though and made the cord too short on one side so it is not as convenient as I hoped. So I only turn it on for road trips and even then I did not want the potential of a wear issue from plugging and unplugging so much.

Mikael48 said:

Remove it, unless it has the auto-off mode. All other dongles will flatten the 12v battery.

Cycling the 12v battery via the automatic top-up should be avoided, it degrades the lead acid battery chemistry.

GDS official diagnostic software can retrieve detailed 12V battery data 30 days back, including battery drain caused by any aftermarket devices:

12V Aux GDS-M BATTERY DIAGNOSIS FUNCTION

Hyundai GDS is the diagnostic software used by dealers. Albeit expensive, GDS appears to be available to DIY owners. It requires a special OBD J2534 pass through device, and a subscription payment to Hyundai. (FWIW, not too many owners go this far, the CarDAQ-Plus 3 is on sale cyber Monday...

www.ioniqforum.com

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This is the reason I made the decision to go with a LifePo from the get go... plus the OEM battery fits in my Miata. But another advantage is the low voltage disconnect and "self jump start" that will allow you to throw the contact again.

I’ve been trying to power a dashcam from the OBD2 port. Troubleshooting has led me to believe that either the port isn’t outputting enough power or that the stupid lojack clone that the dealer had put on doesn’t have good passthrough. So, I guess I’ll removing that next.