Dead Kona EV!

Wildeyed said:
Okay, but why do you feel you need to leave the car "on" when it already has a built in battery saver function?
Click to expand...
Not good enough, the duration the of battery saver function helps but using a meter I can tell when it it time or not, Its just my experience form the past on other EV with a lot of short runs and my driving habits. If you drive longer runs than your intervals to top up should be less, but measuring is the only way to find out for sure.
 
I have to wonder if 12 volt lead acid EV batteries are more prone to acid stratification, the DC to DC converter simply responds to voltage and I imagine it could be tricked by a falsely elevated surface charge. I have to wonder if the 12 v lead acid battery gets any sort of equalization.
In the end I suspect 12v lithium batteries would be better fit for EVs, unfortunately they are 3-5x more expensive than their lead acid counterparts.
 
Fastnf said:
There is an auxiliary battery saver which charges the battery when it's low but it has to be turned on for it to work. See sec H57 for how to turn it on and how it works
Click to expand...

The manual suggests that this function charges the 12v battery from the high voltage battery, as if that were not the usual case. But I'm pretty sure the car doesn't have an alternator for that purpose! So I'm puzzled as to what can go wrong in the normal course of keeping the battery charged that would require an emergency top-up.
 
The only time I have had a 12V battery die on me was when I left my Prius parked outside in Las Vegas for four days in the summer. (There was a really bad sulfur/rotten egg smell, btw.) It could be you just had the bad luck to get a defective battery.
 
The reality is most OEM batteries are not quality equipment, much like factory tires on new vehicles. I've had a couple of generic OEM batteries on past new vehicles pack it in within 24 months.
 
Kamloops_KoNa said:
The reality is most OEM batteries are not quality equipment, much like factory tires on new vehicles. I've had a couple of generic OEM batteries on past new vehicles pack it in within 24 months.
Click to expand...

My question is what is the purpose of the 12 volt battery. I assume it's there to keep the important non running components running when the car is not running. So how is the 12 volt battery charged when the car is running. No alternator to keep it charged up. How does it get that juice from the main battery to keep it charged.
 
GPM432 said:
My question is what is the purpose of the 12 volt battery. I assume it's there to keep the important non running components running when the car is not running. So how is the 12 volt battery charged when the car is running. No alternator to keep it charged up. How does it get that juice from the main battery to keep it charged.
Click to expand...
The video I posted just above does a good plain-spoken job of explaining some of the reasons.
 
From what I understood, the battery degrades faster on a EV because it is not sollicited enough with high demand voltage requests. On an ICE car, that high voltage request comes from starting the car so it happens often. On a EV, starting your car requires no more oomph from the battery than turning on the radio would.
 
Which is similar to what apu said above using more technical jargon. Frankly, from an engineering perspective, I would be somewhat surprised if the DC-DC convertor (Hyundai call it the 'LDC') relies only on open-circuit voltage to determine the status of the auxillary battery. You would think it would thump it with a load and check the voltage response. Perhaps the right thing to do when this happens to do is call the recovery service so that Hyundai are on the hook for the cost. That will send a message.

Electriceddy, have you done some data logging to check the voltage over many hours?

Wildeyed said:
... The only slightly weird thing I noticed yesterday was that the car appeared to be charging again (green light in the charging port) late last night even though the car was reporting 100% charge already.
Click to expand...
A possiblity is that 100% is only 100%. When it drops to 99.99% the OBC will diligently bring it back again. I think that's normal despite looking a bit clumsy.
 
KiwiME said:
Which is similar to what apu said above using more technical jargon. Frankly, from an engineering perspective, I would be somewhat surprised if the DC-DC convertor (Hyundai call it the 'LDC') relies only on open-circuit voltage to determine the status of the auxillary battery. You would think it would thump it with a load and check the voltage response. Perhaps the right thing to do when this happens to do is call the recovery service so that Hyundai are on the hook for the cost. That will send a message.

Electriceddy, have you done some data logging to check the voltage over many hours?


A possiblity is that 100% is only 100%. When it drops to 99.99% the OBC will diligently bring it back again. I think that's normal despite looking a bit clumsy.
Click to expand...
Hyundai Roadside Assistance footed the bill for the flatbed tow (40km) and the warranty is going to be in play in whatever remedies are necessary to get me on the road again.

If we've apparently established that 12 volt batteries on EVs are a weak link ( something I'd literally never heard mentioned before yesterday!) then do I have to worry about this happening every 7 months going forward or is it more likely a bum battery, a one-off?

Regarding the 99.9% thing... Given the eventual dead battery, is it possible that rather than " topping up" to 100% maybe the car detected a (12 volt) battery drain and was trying to compensate?
 
KiwiME : no data logging , i just monitor with my Fluke 97b on occasion , sometimes when vacuuming the car or checking other items.
My first Leaf died within 3 weeks of purchase back in 2013 and I quickly learned to compensate with a battery maintainer.
What would be a good thing to carry if travelling in the boonies is a power pack with enough energy to power the start up sequence just in case. After running for a while the 12 V battery should be OK unless there is a defect or a short in the system. I know on the UK forum there was discussion on that as well but I haven't followed up on the best option.
 
Wildeyed said:
Regarding the 99.9% thing... Given the eventual dead battery, is it possible that rather than " topping up" to 100% maybe the car detected a (12 volt) battery drain and was trying to compensate?
Click to expand...
Absolutely right, that would would easily do it.

There was info on FB today that the LDC (Hyundai's name for the 12V charger unit) can pump out 1300 watts. I know it's fused at 200 amps so that sounds plausible.
Figure that 1300 W / 14.4 V = 90 amps, assuming no sag from the LDC. So, in utility mode where vehicle loads are minimal, that's a fair amount of power to run your campsite or whatever.
 
KiwiME said:
Absolutely right, that would would easily do it.

There was info on FB today that the LDC (Hyundai's name for the 12V charger unit) can pump out 1300 watts. I know it's fused at 200 amps so that sounds plausible.
Figure that 1300 W / 14.4 V = 90 amps, assuming no sag from the LDC. So, in utility mode where vehicle loads are minimal, that's a fair amount of power to run your campsite or whatever.
Click to expand...
Inverter in case of power failure for a critical load at home
Do you have the schematic/specs from the service manual available?:cool:
I intend to install one to supply at least a small sub HP motor (maybe 300 W) for b/up emergency heat off my wood burning fireplace insert.
 
Last edited:
I'm still a bit unclear on how recharging of the 12-volt battery works.

1. Is the Aux. Battery Saver+ feature they only way the battery can get recharged (from the main Lithium battery), or does it recharge while you're driving it like the battery of an an ICE car would?

2. What is the difference between Cycle Mode and Automatic mode for the Battery Saver+ feature, and which is the preferred mode to keep it in?
 
Jamas said:
I'm still a bit unclear on how recharging of the 12-volt battery works.

1. Is the Aux. Battery Saver+ feature they only way the battery can get recharged (from the main Lithium battery), or does it recharge while you're driving it like the battery of an an ICE car would?

2. What is the difference between Cycle Mode and Automatic mode for the Battery Saver+ feature, and which is the preferred mode to keep it in?
Click to expand...

The DC to DC converter runs whenever your car is turned on and likely in motion, the aux battery saver is just software that engages the converter when it detects low voltage from the lead acid battery during periods when the car is turned off. I suspect the utility mode is useful when the car is turned on but not in motion as the converter would not otherwise engage.

I am going to speculate automatic mode engages whenever it meets low voltage criteria, while cycle is just that, a schedules duration and frequency of charge not dependent on actual battery voltage.
 
apu said:
The DC to DC converter runs whenever your car is turned on and likely in motion, the aux battery saver is just software that engages the converter when it detects low voltage from the lead acid battery during periods when the car is turned off. I suspect the utility mode is useful when the car is turned on but not in motion as the converter would not otherwise engage.

I am going to speculate automatic mode engages whenever it meets low voltage criteria, while cycle is just that, a schedules duration and frequency of charge not dependent on actual battery voltage.
Click to expand...
So is there a recommended mode (automatic vs. cycle)?
 
R P said:
Just checked mine, and all I see is on or off, no auto or cycle mode.
Click to expand...
Strange as the manual (Page H57) states:

Mode
* Cycle Mode:
When the POWER button is in the OFF position with all doors, hood and liftgate closed, the Aux. Battery Saver+ activates according to the auxiliary battery status.
* Automatic Mode :
When the POWER button is in the ON position with the charging connector plugged in, the function activates according to the auxiliary battery status to prevent overdischarge of the auxiliary battery.


So do both of these actions happen automatically as the need for a charge arises?
 
Jamas said:
Strange as the manual (Page H57) states:

Mode
* Cycle Mode:
When the POWER button is in the OFF position with all doors, hood and liftgate closed, the Aux. Battery Saver+ activates according to the auxiliary battery status.
* Automatic Mode :
When the POWER button is in the ON position with the charging connector plugged in, the function activates according to the auxiliary battery status to prevent overdischarge of the auxiliary battery.


So do both of these actions happen automatically as the need for a charge arises?
Click to expand...
Sounds like it. Makes you wonder why there's an on/off option in the first place though.
 
You must log in or register to reply here.
Back
Top