Question about 12v auxiliary battery 2023 Kia Sportage PHEV
I have had car for about a year without any problems. I had car plugged into trickle charger for about two days. It had fully charged after 10 hours.
On second day, I went to unlock car. No response. Nothing worked. My Kia Connect app (from previous day) showed no error messages and showed main battery fully charged. My Kia Connect full info pack had expired a few weeks ago - so I don’t have full interactive experience. I also had my car serviced (first time) at dealer for its one year anniversary. Everything was fine per the dealer.
To get into car, I used the emergency key access (pulled plastic cover on driver door handle). Everything dead.
I tested battery using terminals under hood which showed 3.5 volts.
I then took a spare battery and connected to the + jump contact and - on metal frame bolt. Car immediately came to life and responded for me to start car. It immediately started in EV mode; and after a minute the ICE kicked on. I only ran car for 5-10 minutes (jump battery disconnected immediately after starting).
With car off, I rechecked voltage and it was was 12 volts.
My hypothesis is either:
1. New parasitic trickle draining of 12 volt battery from something ? I have a wireless CarPlay adapter that’s always plugged in….but it seems to go off after car off for a few minutes; and even if it still draws, it has to be a tiny draw- and it hasn’t had a problem for a year. I also installed (myself) a homelink mirror and slaved the power off of map light. Mirror powers off when car locked. Not sure- but wonder if map light power automatically powers off if car off by unlocked. I also looked up on internet and someone mentioned the Smart Gate sensors can cause this problem (only one poster stated this….)
2. Battery is defective. (Never super cold ; and based on car turning on without “cranking”, batteries usually don’t catastrophically fail - and then works normal for next two days….in even colder weather …)
So it got me thinking; and I’m having a hard time finding the facts about 12v battery:
1. the 12 volt battery is needed to get into car and start car- regardless of EV or ICE mode. And if “dead”, there is NOT a reset switch (to my knowledge ) or jump start switch that uses the big battery to start car. So why not? The HEVs have this switch. Explanation is voltage is different (48v)…..but why can’t they implement this with resistors to decrease voltage vs needing to jumpstart car????!!!
2. The car started with the jumpstart battery…..but I’m thinking it does not need to be a high amperage battery for ice starter- just to start electrical systems. If true, maybe just keep a small low amp 12 volt battery (like a home alarm backup battery in car (with cables) so I’m never stranded. Thoughts?
3. How is the 12 volt battery maintained when car is normally functioning? Is there an actual traditional alternator and belt vs charging off of EV battery?
I have had car for about a year without any problems. I had car plugged into trickle charger for about two days. It had fully charged after 10 hours.
On second day, I went to unlock car. No response. Nothing worked. My Kia Connect app (from previous day) showed no error messages and showed main battery fully charged. My Kia Connect full info pack had expired a few weeks ago - so I don’t have full interactive experience. I also had my car serviced (first time) at dealer for its one year anniversary. Everything was fine per the dealer.
To get into car, I used the emergency key access (pulled plastic cover on driver door handle). Everything dead.
I tested battery using terminals under hood which showed 3.5 volts.
I then took a spare battery and connected to the + jump contact and - on metal frame bolt. Car immediately came to life and responded for me to start car. It immediately started in EV mode; and after a minute the ICE kicked on. I only ran car for 5-10 minutes (jump battery disconnected immediately after starting).
With car off, I rechecked voltage and it was was 12 volts.
My hypothesis is either:
1. New parasitic trickle draining of 12 volt battery from something ? I have a wireless CarPlay adapter that’s always plugged in….but it seems to go off after car off for a few minutes; and even if it still draws, it has to be a tiny draw- and it hasn’t had a problem for a year. I also installed (myself) a homelink mirror and slaved the power off of map light. Mirror powers off when car locked. Not sure- but wonder if map light power automatically powers off if car off by unlocked. I also looked up on internet and someone mentioned the Smart Gate sensors can cause this problem (only one poster stated this….)
2. Battery is defective. (Never super cold ; and based on car turning on without “cranking”, batteries usually don’t catastrophically fail - and then works normal for next two days….in even colder weather …)
So it got me thinking; and I’m having a hard time finding the facts about 12v battery:
1. the 12 volt battery is needed to get into car and start car- regardless of EV or ICE mode. And if “dead”, there is NOT a reset switch (to my knowledge ) or jump start switch that uses the big battery to start car. So why not? The HEVs have this switch. Explanation is voltage is different (48v)…..but why can’t they implement this with resistors to decrease voltage vs needing to jumpstart car????!!!
2. The car started with the jumpstart battery…..but I’m thinking it does not need to be a high amperage battery for ice starter- just to start electrical systems. If true, maybe just keep a small low amp 12 volt battery (like a home alarm backup battery in car (with cables) so I’m never stranded. Thoughts?
3. How is the 12 volt battery maintained when car is normally functioning? Is there an actual traditional alternator and belt vs charging off of EV battery?
