[avh]

The car has the correct voltage for charging AGM batteries, but when the car sits idle for a few days or even if is driven for an hour a day, is not getting charged long enough to reach 100%. Is better for any acid battery to be recharged fully after a discharge. Unlike AGM, my car is able to charge regular flooded fully.

 

[avh]

I'm not sold on lithium or AGM due to how the resistance is different and, hence, charging is going to be handled differently. Maybe that's not an issue. For now, I'm just keeping a charger in the frunk and if I have to use it, then I will make the jump to lithium (Ohmu now that they've updated their batteries with logic specific to the EV6).

Looks like the car uses the same charging profile and is not addaptiing if internal resistance is different. Other cars like some Toyota with start/stop technology, keep track of how old the battery is and charges it differently as it ages. For such cars the dealer needs to reset the timer or new batteries will be ruined prematurely.
I saw some interesting discussions on Toyota forums about switching from EFB to AGM and the consensus seems to be to stick with the chemistry the car is programmed to charge. LiPO is the wildcard because they are actively managed by the internal BMS. However before I trust LiPO I would like to see some major manufacturers stepping in.

I was reading somewhere that in Europe car manufacturers only use AGM and EFB and the ratio seems to be 50/50. EFB are heavier duty flooded acid that can keep the electronics going on an ICE car while the engine is stopped at a red light for example and not be damaged by deeper discharge.

 

[JK-KIAEV6]

Both valid points. However, the car can't charge the 12V battery just because of a design problem?? It just seems like a big battery with gazillions of electrons, could send some to the little battery as needed. Am I over simplifying?

Agree it should and would be so easy to think this way but for some reason only known to Kia they have not offered this.

 

[alexw]

Agree it should and would be so easy to think this way but for some reason only known to Kia they have not offered this.

They do - when driving and when the car is asleep via Aux Battery Saver+. It just doesn’t work reliably.

 

[spinfire]

Aux Battery Saver works exactly as designed. The problem is people think it will save them from 12V batteries with severe sulfation and bad cells. The aux battery saver will stop trying to charge a battery that has reached this level of failure. By design. Because your failed 12V battery needs to be replaced, not charged more.

You see it all the time on Facebook groups or even here. “I jump my 12V battery every few days there must be something wrong with how the battery is charged by the car.” NO. A lead acid battery that is being discharged below even 50% on a weekly basis is wrecked. You need to replace the battery.

The correct response after needing to jump start a car is to drive it to an auto parts store and buy a replacement battery, whether it’s an EV or ICE. Or try the dealer but if they’re telling you your service appointment is a month out just give up on them. You can keep your old Kia battery and put it back in just before the service appointment if you really want to go this route.

You don’t need to keep a spare AGM battery in the trunk. That’s silly since they will age even without being used. But you do need to act promptly if your 12V battery starts failing, not keep jumping it and hoping something will magically fix itself in the battery.

 

[alexw]

Aux Battery Saver works exactly as designed.

OK I guess I agree with that - it's just designed badly. It's naive and dumb to assume that the battery is faulty simply because it drains fast, especially when you've got a coulomb counter attached to it that could determine whether the load is internal (a fault) or external (the car behaving badly, which it DOES sometimes, or a legitimate external load).

If ABS+ just stuck to the script and ALWAYS recharged the 12V when the SOC hit 80%, most of these battery problems would go away.

 

[spinfire]

I understand why it wants to self preserve the HVB if it thinks it has a failing lead acid, or an unexpected vampire load, but it seems informing the driver through a fault code or Kia Connect while still letting the HVB go as low as 30% seems to me like a better design than not informing the driver and continuing to charge it until it gives up after a certain number of tries. I don’t see this as a huge flaw but hopefully it can be improved upon in future model years.

 

[TheEV6lemon]

Aside from the possibly unnecessary cost involved, do you think it's a good idea to replace the original 12V battery "just in case" it might fail? My car is a Jan. 2023-build EV6 GT-Line RWD and has not had a battery problem. I would install a brand name AGM type battery and do it myself without the dealership being involved.
A few factors to consider: I believe that the AGM can withstand a deep discharge better(?). I do live in a hot climate where it is recommended to replace any car battery every 2 to 3 years, although mine is less than a year old. I do carry a jump starter in the frunk but have never used it. I know it's kind of like asking if I should buy more life insurance but maybe you have a recommendation on this based on fact. Thanks.

Late to the party here but ours was a '23 ev6 gt line 1 AWD. 64000 km, had to have ICCU replaced a few months ago and just had to replace the 12V battery today. Over the past 2 months it has been dying on us, and until today we had to regularly plug it into a trickle charger to keep it up to snuff because the car wouldn't charge it enough for some reason. Today it stopped taking a charge so just bypassed the dealer and trying to fight those idiots and bought an AGM.