12V battery

[KiwiME]

So here are a few more graphs as requested, we just had the car parked for a few weeks and it went into a recharge 'once a day' mode, of around a 25 hour period. Each time it hits 12.73 volts the DC to DC charger steps in and brings the 12 Volt battery back up to 14.78.
... us engineering types just love it...

Thanks for posting the data. The BM2 really is a handy little device and it's convenient to be able to sneak up on the car without disturbing anything and confirm its status.

After I get mine done, I will probably still keep up my usual habits of leaving the car "on" for a couple of hours ...

Just a note in case we didn't cover it before that Utility mode does not stop charging after 30 min as Run mode does. ... assuming that this policy remains after the update.

I see perhaps slightly less jitter and a slower rate of discharge possibly because my version is not equipped with BlueLink. No software update applied yet ...

 

[electriceddy]

Thanks for posting the data. The BM2 really is a handy little device and it's convenient to be able to sneak up on the car without disturbing anything and confirm its status.
Just a note in case we didn't cover it before that Utility mode does not stop charging after 30 min as Run mode does. ... assuming that this policy remains after the update.

I see perhaps slightly less jitter and a slower rate of discharge possibly because my version is not equipped with BlueLink. No software update applied yet ...
View attachment 8682

Wasn't aware of that, thanks!

 

[wizziwig]

So even after the BMS update, the 12V Aux Battery Saver still eventually reverts to the old schedule of 24-hours between charge cycles? Then what is the point of initially waiting only 4 hours between charge cycles with this update?

 

[KiwiME]

I think we have yet to understand the strategy.

 

[electriceddy]

Possibly this is geared towards a vehicle that makes a lot of short trips not enough to charge the 12 V battery. After 2.5 days they might assume it will be plugged in and topped off that way or be put in "storage mode" with the fuse panel switch off.
The other possibility is they just want us to drive our cars more

 

[electriceddy]

After getting the car back from the software update the battery voltage is at 12.25 V (low) so I have it parked in run mode to top it off. Note the voltage is only 13.4 V where it was 14.7 v and higher before. I will check in an hour to see if it is still charging at the same voltage to verify if the 30 minute limit is still applicable. A side note , in utility mode the voltage is the same at 13.4 V.

 

[electriceddy]

Just went out and measured after parked in "run" mode (approx 3 hours) and still reads 13.4 V. I shut the car off and the battery resting voltage now sits at 12.76 V. I am sure it will reduce to a lower level after a couple of hours, but at least I can confirm that the 12 V battery does not stop charging after 30 minutes when parked in "run" mode. Probably another change from the software update.

 

[R P]

Just checked mine in the garage, and it read 12.44V or 80%. Surprised it wasn't higher since my wife was just out this morning driving (about 1 hour drive time). Having said that I have never had a battery problem, so not sure how low it ever got. Will have to check it more frequently to be sure. And I have never seen the grille charging light come on, although not that I am checking regularly for it. But with this BMS update, would think it should come on more frequently.

With my other ICE car, I have an onboard display (USB) which I can see every time I turn on the car. It is regularly at around 12.2V (60%) when I get ready to start the car, and then charges at 14.3V most of the time while driving. It never gets down to float charge (13.2) unless on a long day trip. That is normal for it. And never had a low battery issue with that car either. This car does not get driven frequently and sometimes sits for weeks at a time between drives.

 

[Toolworker]

After the BMS update, it appears to check the voltage every four hours. If it's above some level - looks like around 12.6v - it goes back to sleep. Otherwise it charges for 20 minutes every four hours until it's happy again. Sometimes it charges for more than an hour the first time.

And something else is going on, because in quite a few of those four hour periods in the above graphs, the voltage bumps up about 0.15v halfway through and the slow discharge flattens out. So something must be using power for the first two hours and then turn off.

Turning back to my repeating dead 12v battery problem, "Plus ça change, plus c'est la même chose." I was hoping this reprogramming would solve it. But no such luck.

​

The car was plugged into my AeroVironment EVSE, which seems to be necessary for the problem to occur. Around 3 in the morning it started to drain. Fortunately I looked at it around noon and saw around 6.7v on the BM2 app - maybe too low for the BM2 to record (the flat line from 7:45 on) but enough to hold its memory. A few hours later there would have been a dead car and no data.

I don't know what to make of the wild lines between 6:45 and 7:45. Could that recording be inaccurate? Or is the new charging algorithm trying to respond to the low voltage, and possibly fighting with the EVSE as I have seen before?

In any event, the key takeaway is the death spiral still occurs. And it started much earlier than 6:45. The new protocol activates every 4 hours, but starting around 19:00 on 7/2 something happened every 2 hours - ticks around 19:00, 21:00 and 23:00, then that little bump up at 01:00, and the death spiral starting at 03:00.

So now I will see if the dealer I'm now using can get all these observations to someone who will say something more useful than "Bring it in and we'll check out the battery."

 

[electriceddy]

View attachment 8716
After the BMS update, it appears to check the voltage every four hours. If it's above some level - looks like around 12.6v - it goes back to sleep. Otherwise it charges for 20 minutes every four hours until it's happy again. Sometimes it charges for more than an hour the first time.

And something else is going on, because in quite a few of those four hour periods in the above graphs, the voltage bumps up about 0.15v halfway through and the slow discharge flattens out. So something must be using power for the first two hours and then turn off.

Turning back to my repeating dead 12v battery problem, "Plus ça change, plus c'est la même chose." I was hoping this reprogramming would solve it. But no such luck.

View attachment 8718​

The car was plugged into my AeroVironment EVSE, which seems to be necessary for the problem to occur. Around 3 in the morning it started to drain. Fortunately I looked at it around noon and saw around 6.7v on the BM2 app - maybe too low for the BM2 to record (the flat line from 7:45 on) but enough to hold its memory. A few hours later there would have been a dead car and no data.

I don't know what to make of the wild lines between 6:45 and 7:45. Could that recording be inaccurate? Or is the new charging algorithm trying to respond to the low voltage, and possibly fighting with the EVSE as I have seen before?

In any event, the key takeaway is the death spiral still occurs. And it started much earlier than 6:45. The new protocol activates every 4 hours, but starting around 19:00 on 7/2 something happened every 2 hours - ticks around 19:00, 21:00 and 23:00, then that little bump up at 01:00, and the death spiral starting at 03:00.

So now I will see if the dealer I'm now using can get all these observations to someone who will say something more useful than "Bring it in and we'll check out the battery."

I am going to keep my "topping off the 12 V while parked in run - or utility modes for a couple of hours a month" scenario as I have become accustomed to over the years . Both my Leafs had the same issue even with their own "software updates" applied.
Still no answer on your EVSE battle however is kind of a letdown.

 

[KiwiME]

...
The car was plugged into my AeroVironment EVSE, which seems to be necessary for the problem to occur. Around 3 in the morning it started to drain. ...

What was the programmed starting time for AC charging?

...
I don't know what to make of the wild lines between 6:45 and 7:45. Could that recording be inaccurate? Or is the new charging algorithm trying to respond to the low voltage, and possibly fighting with the EVSE as I have seen before? ...

The 15.0 V peak indicates to me that it's likely not real. The BM2 may not be functioning even though it's able to retain its memory.
The following ramp up after the jump start looks as it should - the LDC current limiting due to the depleted aux battery then constant voltage at the normal charging level of around 14.8 V.

It is puzzling that the Kona did not try to save itself during the death spiral.
Were you ever able to try a different brand EVSE on the same 240V supply, other than the portable unit? And if I recall the portable unit works correctly?

 

[Toolworker]

Just a note in case we didn't cover it before that Utility mode does not stop charging after 30 min as Run mode does. ... assuming that this policy remains after the update.

I can confirm that. I just ran Utility mode for over an hour to recharge my once again dead 12v. battery. (And Bluelink emailed me an "Engine idle alert Notification" every 15 minutes.)

Still no answer on your EVSE battle however is kind of a letdown.

Well, by now I'm used to jump starting it with my mini-jumper battery pack, so I have no fear of getting stranded.

And by now I know to keep the pack hard up against the back of the rear seat. Storing it underneath the cargo area presents a challenge when there's no 12v to open the rear hatch. Don't ask me how I know.

And when I took the car in for the service bulletin, I asked them to note the 12v problem. So now I have two trips to the dealer on record. Unfortunately I will have to take the car back to the dealer in order for them to call their help line, and I'm not going to do that until the virus simmers down. But at least I have a service advisor now that understands the issue.

 

[Toolworker]

What was the programmed starting time for AC charging?

21:00. It can be seen on the 07/01 graph here.

It is puzzling that the Kona did not try to save itself during the death spiral.
Were you ever able to try a different brand EVSE on the same 240V supply, other than the portable unit? And if I recall the portable unit works correctly?

Not quite. I've seen problems with two EVSEs and three circuits. Only the 240v AeroVironment EVSE gets into the death spiral. But using the EVSE that came with the car, sometimes it stopped running ABS+ altogether and the voltage dropped. The graph showed a spike when ABS+ should run, but it doesn't charge. I tested that EVSE on my 120v circuit, my 240v circuit, and my neighbor's 120v circuit, with the same results. (This was before the BMS reprogramming.) See the last few graphs in this post:

... my 12v battery has been slowly discharging for 5 days now without Aux Battery Saver+ running. See graph below.

 

[wizziwig]

View attachment 8716
I don't know what to make of the wild lines between 6:45 and 7:45. Could that recording be inaccurate? Or is the new charging algorithm trying to respond to the low voltage, and possibly fighting with the EVSE as I have seen before?
"

It was around 4 hours since the death spiral started. Probably the battery saver finally woke up as part of the new 4 hour check interval, saw voltage was low, and attempted to charge it. For some reason it failed. Maybe the drain was higher than the charging rate? Won't surprise me if we continue to see lots of dead 12V battery reports next Winter even with this update.

 

[apu]

It was around 4 hours since the death spiral started. Probably the battery saver finally woke up as part of the new 4 hour check interval, saw voltage was low, and attempted to charge it. For some reason it failed. Maybe the drain was higher than the charging rate? Won't surprise me if we continue to see lots of dead 12V battery reports next Winter even with this update.

I don't think you will have to wait that long. I had my first flat battery after the update yesterday(4th in past 6 months), its voltage dropped so low that my lithium battery booster threw an error code and would not even try resurrecting it. I had to get a boost from another lead acid battery. This is getting really annoying Hyundai.

 

[Toolworker]

I don't think you will have to wait that long. I had my first flat battery after the update yesterday(4th in past 6 months), its voltage dropped so low that my lithium battery booster threw an error code and would not even try resurrecting it. I had to get a boost from another lead acid battery. This is getting really annoying Hyundai.

I believe this only happens when plugged into an EVSE. Were you plugged in?

A workaround could be to only plug in when necessary. I don't need nearly the range that the Kona has, so that works for me. I was deliberately leaving it plugged in since the BMS reprogramming, and the problem appeared 8 days later.

When I went in for the reprogramming, I asked the service advisor to note the problem for the record, but I was hoping the reprogramming would fix it so didn't raise the issue with the tech. In retrospect that was dumb, because the only time the tech can access his help line is when he has the car.

 

[apu]

I believe this only happens when plugged into an EVSE. Were you plugged in?

A workaround could be to only plug in when necessary. I don't need nearly the range that the Kona has, so that works for me. I was deliberately leaving it plugged in since the BMS reprogramming, and the problem appeared 8 days later.

When I went in for the reprogramming, I asked the service advisor to note the problem for the record, but I was hoping the reprogramming would fix it so didn't raise the issue with the tech. In retrospect that was dumb, because the only time the tech can access his help line is when he has the car.

No, it wasn't plugged.

 

[R P]

Have you tested your battery? Once a battery has been flattened a few times, they tend to be permanently damaged and need to be replaced. A telling sign is if they charge up quickly to "full charge", which is really just a surface charge, and then quickly drops off to a low level once a load is applied.

And oh, don't take it to Hyundai for testing. Take it to a local battery shop. They would be happy to test it for free, and give you (show you on their machine) an honest answer.

 

[electriceddy]

Have you tested your battery? Once a battery has been flattened a few times, they tend to be permanently damaged and need to be replaced. A telling sign is if they charge up quickly to "full charge", which is really just a surface charge, and then quickly drops off to a low level once a load is applied.

And oh, don't take it to Hyundai for testing. Take it to a local battery shop. They would be happy to test it for free, and give you (show you on their machine) an honest answer.

Sounds like its seen its better days.
I would have Hyundai check the EPCU before just installing a warranty replacement (after getting the battery tested by independent of course)- remembering what happened here:
https://insideevsforum.com/community/index.php?threads/dead-kona-ev.6991/page-8#post-82199

 

[KiwiME]

Just went out and measured after parked in "run" mode (approx 3 hours) and still reads 13.4 V. I shut the car off and the battery resting voltage now sits at 12.76 V. I am sure it will reduce to a lower level after a couple of hours, but at least I can confirm that the 12 V battery does not stop charging after 30 minutes when parked in "run" mode. ...

So, to clarify, the system voltage while actively charging is around 14.7 V, which will provide significant charging amps as required. At least pre-update and from my measurements, in Run and AC/DC charging modes the aux charging period is typically the first 30 minutes only. While driving the LDC subsequently dithers between that and a lower voltage of around 13.1 V to suit system loading. On the other hand, while AC/DC charging that lower voltage is stable. In Utility mode I didn't see any drop from the 14.7 V after the 30 minutes. At 13.4 V you would not see much charging current after it had already been subjected to 14.7 V for 30 min.