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From memory the aux batt is set to on by default, but it is a long time since I looked at the setting. I guess it depends how often the car is left without being driven as to how often you will see the message.
I've never seen this message, however I've seen the green light (in the front Hyundai badge) illuminate on several occasions when the car is parked, which according to the manual means the 12V battery is being charged. The battery saver option is enabled - am I missing something?

John.
 

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I've never seen this message, however I've seen the green light (in the front Hyundai badge) illuminate on several occasions when the car is parked, which according to the manual means the 12V battery is being charged. The battery saver option is enabled - am I missing something?

John.
Sorry, no idea.
 

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What kind of battery is it? What rating?

I wonder if it's a bit undersize. No need to crank the starter but these days there are a lot of 12V electronics running off it.

5A charging is only 60W, which is very low. One headlight can be 60W, so if it's only charging that slowly it's going to go flat pretty quickly. I don't know what the baseline is but with running lights, head unit, radar, ultrasonic sensors, lane departure system, dashboard and whatnot 60W probably isn't far off.
 

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Some BMW 5 series ICE suffer the same flat 12v battery undercharging problems: too smart for their own good.
 

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So I was curious and dug out my little clamp meter and did a few tests on my Kona.
As the meter had to go round the cable from the 12V battery I had to keep the bonnet open which limited my options a little. The car hadn't been used since yesterday though I did put it into AUX mode earlier to test a cigarette lighter accessory for a moment.
The readings are all in Amps DC, - is discharge, + is charge.

With the car locked (bonnet open) -4.1 to -4.9
Car unlocked (door opened then shut) -6.5 dropping to -4.3 when the interior lights go off
Boot unlatched -7.0
Car in drive mode, but no heating +20 (may have been higher - after starting I had to get out and go round to see the reading) but dropping over a minute or two to +9 or so
As above but with heating on +12 and then headlights (LED) on as well +9
I forgot to try with the rear screen heater on.

Conclusions.
The converter can clearly provide at least 20A to the 12V system.
The drop from 20A to 9A is almost certainly the initial rush of a slightly discharged battery with it tailing off to a more normal charge rate which stayed fairly steady.
Even with a bit of load from lights and heater fan (I think the elements are traction battery powered) the charge rate held steady at 9A, but I can't explain the 12A bit.

Sometime I might repeat this test but include the rear screen/mirror heat and also recheck that odd 12A reading.

Observation.
If any door, boot or bonnet is not closed the right hand part of the dash display shows this, even when the car is locked (which I don't think is possible for door or boot). This display obviously needs driving, so some system(s) must also be active which accounts for the 4¼ Amps drain. Those may shut down after a time (I'd hope so) but I didn't wait more than a minute or so. When I did close the bonnet with the car locked the hazards flashed briefly and the display blanked out.
 

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It's a bit odd that it got the car operating but just two miles later couldn't. Did you have a lot of equipment in use - headlights, screen/mirror heaters, etc?
It sounds to me like the HV-LV convertor isn't working hard enough.


I bought one of those packs following previous reports. See https://www.speakev.com/threads/no-power.141250/post-2686830
It could be the HV to LV. The AA guy who got me started was surprised that the 12v was only charging at 6amps.

Yes had lights and heater on, the battery must have been low when I left the garage. I am sure that if I had driven straight home the 18 mile motorway trip would have topped up the battery and I would never have experienced this. Learnt a lesson
 

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Thanks guys, interesting numbers. Today I've bought one of these:


It was the cheapest I could find that was definitely in stock to collect. Credit to Halfords for having a basic but solid jump starter available at 1 hour's notice.

I got back, plugged it in (even with only 50% charge on the starter) and the car sprang into life. I then left it in Utility Mode, manually locking the door with the key part of the key fob, for an hour.

I also put in a voltage display dongle in the cigarette lighter; obviously it didn't do anything before I jump started it, then it showed 14.5V. After an hour, it showed 14.9V.

So basically... if you do short trips with a high load on the battery, you will need one of these (or similar)!

(We actually got a second one too, for my wife's Zoe, as she similarly does about 8 miles each way each day, with lights, heating, radio, demister, etc on).
 

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Noting that the "LDC" as it's called by Hyundai, is fused at 150 A to the 12V system.
Sounds plausible. Car fuses usually seem to be very generously rated compared to their normal load and on that fuse box the power steering has an 80A fuse.
In order to provide discrimination a fuse upstream from another generally needs to be about twice the rating. So 150A is about right to avoid that main fuse from the LDC being damaged or blown by a fault on the 80A PS circuit.
 

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Not wanting to tempt fate but I have just put a CTEK charger on mine and it started charging from a fairly low number ( 3 on the CTEK scale). Like any 12v battery it probably needs a boost charge in the run up to winter.
I have had the car for 6 months now, most of the runs are 5 miles ish with one 40 mile run per week. In reality, as with an ICE, the runs are not sufficient to get the battery fully charged. Nevertheless, the charging of the 12v battery, from the traction battery, has worked over the last 6 months, in my case.
 

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So basically... if you do short trips with a high load on the battery, you will need one of these (or similar)!
I am still awaiting a delivery date for my EV but SHOULD be early 2020.
Reading this post with great interest and thinking one of these units would be a good investment / back up for my EV.
I understand that these type of units provide a instant boost to the original12 volt car battery when a "Jump Start" is required, by connecting the 12 volt battery, then pushing the "Boost" function button.
Then a normal ICE can then be cranked over on the starter of the car.
Is this the same process for "Jumping" an EV ???.
Do you connect the unit and hit the "Boost" button, or do you just connect the unit and wait a while until the cars battery has received enough power from the boost pack ?.
Sorry, never owned an EV or a boost pack !.
But I could see one of these being a great way of avoiding a long wait for the rescue services, for what is a 10 second job when they do arrive.
Different system I know, but it feels very strange that you are "Literally" sitting on all that energy stored in the HV pack, and here we find the small 12 volt lead acid battery has brought the car to a complete and utter stand still !.
Crazy :eek:.
 

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Don’t think the ‘boost’ function would be necessary. You just need to get a 12v supply to the car’s electronics so it will start. Then the main battery takes over. However, I think that if I had to use this my next stop would be for a replacement battery!
 

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Where's @mikeselectricstuff ? He's an expert on this sort of stuff.
There is a post here from a while ago where I did some measurements and logging of the 12V usage. The TL;DR is that it takes a few minutes for all the car's systems to fully turn off and reduce draw to an eventual figure below 20mA.

From what I've seen on several posts in various places, I'm fairly sure there is some rare set of circumstances in which the car doesn't go fully to sleep, causing battery drain and also preventing the normal 24 hour top-up that occurs in sleep mode.

The other observation is the "topped up" message on the dash is completely random. I've seen it after being parked for 30 mins, and not had it when car has been left unused for a week.
 

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BTW if you want to do measurements with the bonnet up, you can use a screwdriver as a fake bonnet latch loop to put the latch into locked position so the car thinks it;s closed.
 

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A thought on booster packs etc. to rescue the situation - as you don't need the high cranking current to start an ICE engine, a significantly smaller ( and safer) backup battery pack would probably do the job.
 

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Agreed, but I think the one I got is about as small as they go.
Some people have suggested using phone extender packs, but by the time you've bought that and then sorted out connectors to clip to the car battery, etc, it's not going to be any cheaper. The 'proper' jump ones may also have overload and reverse polarity protection.

Although the cranking current isn't needed there can also be a significant current draw. If the car battery is down to 6V or so then when the 12V booster is connected a lot of current will flow into the car battery to start recharging it, so the booster can't just supply 5A or whatever to run the car's initialization circuits.
 

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Don’t think the ‘boost’ function would be necessary. You just need to get a 12v supply to the car’s electronics so it will start. Then the main battery takes over. However, I think that if I had to use this my next stop would be for a replacement battery!
Can somebody confirm my understanding here please.
So, when your 12 volt battery reports its flat and is unable to boot up the car.
You connect the "Power Pack" to the 12 volt battery of the car and then power is transferred directly from the power pack and into the original car battery.
No reason to touch the Boost button then ?.
Energy from the Boost pack is put straight into the lead acid battery as soon as the cable clamps are connected.
 

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Energy from the Boost pack is put straight into the lead acid battery as soon as the cable clamps are connected.
That's usually the case. Mine doesn't have a 'boost' button.
I suspect it's just a fancy name for a button/switch that makes the circuit when you choose rather than as soon as you connect it up. But you'll need to read the instructions for your specific device to find out.
 
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