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Discussion Starter · #1 ·
I have a 2020 Kona EV that I park indoor with the hood under a hanging cabinet. You can only open the hood about 12-15 inches because of the cabinet.
I went to my car and found the 12v battery dead. Door locks (interior button and key fob), interior lights, push start button, radio, drive selector (P, D, R, N), etc. all dead. Big battery had plenty of charge when I parked it.

I managed to prop open the hood far enough to get a multimeter in there and saw that the 12v battery was about 7 volts. I again struggled, but got a trickle charger in there, charged the battery for a bit and was then able to start the car and all was good.

So, my question, for future reference:
How can I open the tail gate to retrieve a pair of jumper cables to charge/jump my 12v battery AND how do I put the car in neutral so I re-align the car can get assistance from a good samaritan when the 12v battery is dead?

From my research, nothing works with a dead 12v and thus I apparently can't do the above two actions needed to fix the problem. I'd even be willing to crawl through the backseat to open the tailgate from the inside, but that doesn't seem possible either!
This seems to be a major design flaw...
 

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Sorry I can't answer your question but I am concerned about how your 12volt battery can go so flat. I understand that when the car detects a low voltage in the 12 volt battery it uses the main battery to top it up so if the main battery is good how would it let the 12 volt battery get so low.
 

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Discussion Starter · #3 ·
Hi Keith,
From my online research, it appears the factory 12v is not the best quality. It's physically pretty small and thus doesn't have a lot of reserve or cold cranking amps (I understand that CCA is not actually a neccessity in that definition). Two-ish years seems to be an average life expectancy for the factory battery. Mine lasted almost 2.5 years.

I had the doors/tail gate open for an hour plus (so interior lights were on until they auto-off'd) while I was vacuuming the interior. ...dog hair takes a while to get out. I also used the power seat function to aid in access for vacuuming. I did close all the doors several times thus I cycled the interior lights several times. I did not have the stereo on. That's the only battery drain I can think of.
 

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I've seen no evidence that the Rocket battery is of poor quality and I've passed 4 years. The weakness is purely about the car's inability to detect when it needs charging or support, such as when a door is left open for even a short time.
 

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Discussion Starter · #5 ·
I've seen no evidence that the Rocket battery is of poor quality
Kia ora!
So, you're effectively telling me a 2.5 year old battery that can't keep three LED interior lights on, and move an electric powered seat a couple of times is a good quality battery?
Don't forget, this battery voltage was down to ~7v after well less than 2 hours. I've left incandescent headlights and a radio on for that longer than that and could still crank a starter motor on an ICE car.
 

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I just replaced my 12V battery after a little over three years. My understanding is the Rocket IS a medium level battery and with the excessive load that a 12V battery deals with in an electric vehicle , it should last three to four years. You’ll be very sad if you push the limitations of the battery and the vehicle quits responding. It’s dead in the water if that battery isn’t putting out close to 12 volts . Fortunately for me it happened in my garage while I was on vacation. The dealer had to order the battery(rediculous), so I purchased an interstate battery from Costco(much cheaper) and installed it myself in 10 minutes. Buy a group 121R standard battery and all is well.
 
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