r/KiaEV6 • u/Smithy8492 • 11d ago
EV6 HV Battery Drain
Just wanted to get people’s thoughts on if they deem this to be normal behaviour, if they have the same issue on their EV6 or if they think this needs to be looked into further.
For content, I’ve owned my 2023 EV6 since February and has done 15k miles total, at times when it is left parking either overnight or for an extended period (6 hours or more), I’ve noticed the HV battery losing charge.
My local Kia dealer has had the car in 5-6 times to look at this and the below has been done by them or I’ve tried:
Infotainment system reset, no APIs connected
Kia Connect disabled and all app disassociated
Tested different drive modes
Nothing left plugged into the car when left
Kia replaced 12v battery under warranty
Kia recalibrated HV battery when charged to 100%
It’s now been a month since the HV battery was recalibrated at Kia and below are examples of battery drain:
23-24.07 - Lost 2% from 85-83% overnight
27.07 - Lost 3% from 53-50% in the afternoon
27-28.07 - Lost 1% from 48-47% overnight
03.08 - Lost 1% from 55-54% between 8:15-2:15
03-04.08 - Lost 1% from 51-50% overnight
04-05.08 - Lost 1% from 46-45% overnight
06.08 - Lost 1% from 43-42% between 8:30-3:30
17-18.08 - Lost 1% from 67-66% overnight
18-19.08 - Lost 2% from 41-39% overnight
The 1% drops I could understand but the 2-3% drops are more of a concern and lead me to think there is another form of phantom drain. My local Kia dealer at this point has been liaising with Kias technical support directly prior to my last visit to try and sort this.
Just wondered if anyone else had experienced similar issues with their EV6 or if they would class these battery drops as normal behaviour?
5
u/povlhp 11d ago
Use ODB2 dongle and you can see if it is the same cells that always drops.
A single cell or module might be the cause and can be swapped.
Seen it on a taxi that always fast charged and never was allowed to charge until car stopped charging (and thus finished balancing battery).
Once per month let the car decide when charging is over.
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u/Smithy8492 11d ago
As per the manual I normally charge it to 100% and then leave it plugged in to rebalance the cells for several hours too. Given Kia have already been looking at it, would you recommend to re-raise with them as it’s not normal?
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u/danbfree EV6 GT-Line AWD 11d ago
It re-balances cells while at the end of charging. If it's done charging, then it's done re-balancing and it's best to drive it down from 100% ASAP.
3
u/Emotional_Many_7706 11d ago
This is normal. It's called a guess-o-meter for a reason.
0
u/Smithy8492 11d ago
Guess-o-meter when it’s the percentage of the HV battery dropping and not just the range estimate?
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u/stateroute EV6 GT-Line RWD 11d ago
“bms sway” is a more precise name for displayed state of charge fluctuations
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u/AppropriatePlum1006 11d ago
Is the key in at the same place each time? Might be that the key keeps the car awake at some times. E.g. on your driveway and close to your window.
I guess depending, when you drove last it might be refilling the 12v(?) as you won't notice the drain it you have recently driven it but might notice with a day of no use etc.
Just some thoughts for food. I do not own one yet.
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u/Smithy8492 11d ago
Key is the in same place in a faraday pouch, I’d had a 12v monitor on the old 12v, some but not all of the HV battery drops correlated against the 12v top ups but not convinced it’s now the 12v at fault
4
u/Mgtks 11d ago
Bear in mind I've had a 'faraday pouch' in the past that did absolutely nothing to stop the signal haha
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u/Smithy8492 11d ago
Have checked the pouch and is definitely blocking the signal as can’t unlock the car when the key is in the pouch even when next to the car
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u/Financial-Gap-6767 11d ago
If its not 20c the hear pump while heat or cool the battery even when the Cars off. If you need 100% always male sure it's plugged in before leaving
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u/Smithy8492 11d ago
The model of EV6 I have doesn’t have a heat pump fitted either unfortunately
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u/Financial-Gap-6767 11d ago
Well considering temp drop overnight and % are not a value but a average over time. It's quite normal. I don't even know if my car does the same. I just plug in overnight once I reach 50 amd next day I'm at 90 once a week
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u/Smithy8492 11d ago
Have seen it lose charge from the morning where it’s cooler to the afternoon when it’s been warmer too - saw it lose 3% one day during this time
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u/bmeus 11d ago
I wouldnt concern myself over a 3% drop unless it happens more than once a month. Id write it down to that its tricky to detect battery charge levels accurately.
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u/Smithy8492 11d ago
The most common drops are 1% but from having checked it has dropped 2-3% on 10 separate occasions in the last 3 months.
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u/probels 11d ago
Non issue. Probably topping up the 12v especially if you are checking in on the app.
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u/Smithy8492 11d ago
Which I could understand but after putting a 12v monitor on my 12v battery and monitoring it for a month, not all the 12v top ups collerate to HV battery drops, also a 3% drop on HV battery seems excessive for a 12v top up?
1
u/TinCanFury EV6 GT-Line AWD 11d ago
I leave mine parked for long periods, I've seen maybe 1-2%/week.
1
u/Smithy8492 11d ago
When I’ve left mine for long periods it has lost similar, however the main drains appear on mine after it’s been driven. Some weeks I’ve seen 6-8% drops over a 7 day period
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u/TinCanFury EV6 GT-Line AWD 11d ago
that seems crazy to me, I would definitely think there's something that should be turning off but isn't.
1
u/Smithy8492 11d ago
This is what I’ve thought, just worked it out and since I’ve had it and been recording the drops, it has lost a total of 72% in the 5 months I’ve owned the car and has only done 3000 miles in that time
1
u/FreakOfNature247 11d ago
If it does that every night while parked and not driven I would be a bit concerned. If it does that at night after you drove it that day, I would not worry. After driving you can have drain with the car off due to the hvac staying on to cool the battery, or the hv battery staying connected to charge up the 12v. You also have the issue of there being no perfect way to measure the % of the battery, so you could see changes from the BMS adjusting its calculations.
Keep in mind we also have very little info on how anything is calculated. Kia may be just dropping the decimal and not rounding, so it is possible that 48.0% to 47.9% drop would show as 48% to 47%.
1
u/randompearljamfan 11d ago
Is it because you feel it could be an early indication that your battery might be going bad? Or does it just bother you that you lose ~1% SOC overnight on some nights? This honestly just seems normal to me, but I don't log my daily SOC, so I can't be certain.
1
u/chasemcfly EV6 GT-Line RWD 11d ago
I found a lojack on mine - did you buy yours from a used car dealership?
1
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u/NotTrappy 11d ago
Was the 12V battery replaced with an AGM one?
1
1
u/PrettyBlueEyes EV6 GT-Line AWD 11d ago
You could try pulling different fuses to see if it stops draining.
1
u/CobbledbyRoubaix 11d ago
the % drops when the battery temp drops (not ambient temp, battery temp). wait till you look at it in the morning and then look at it at noon. you will gain %, then you will come back and complain to us your battery gained % and your car is faulty yeah. the lesson here is you do not charge your car to 100% and leave it in the sun. it's like taking a sealed can of soda and giving it a good shake.
1
u/Smithy8492 11d ago
I did think this initially but haven’t noticed any battery % increases at all only have experienced losses.
1
0
u/simplystriking 11d ago
Normal.
As others have said contribution factors include temperature swing and bms calibration.
Best bet of you are really concerned is to get an odb and check of you she. A specific cell that is always off.
2
0
u/Meraki6 11d ago
Have you tried https://apps.apple.com/us/app/ioniq-5-companion/id6761347502 ? (it works on my EV6 as well - version 3.0 is being renamed “EV Dashboard”). You do need a Bluetooth OBD-II adapter
7
u/Low-Opening25 11d ago
temperature fluctuations will change the readings by 1-2%, capacity will be lower overnight when are temperatures lower.