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2021 Polestar 2
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Discussion Starter #1
Accepting I haven't yet got my car, I have read a number of threads about battery drain issues that may/may not have been solved by the latest recalls etc. I was just doing some research this morning and wondered whether it was worth an investment in some form of portable battery booster/starter or charger? Having never owned an EV before is the booster something that would assist in times of trouble given that it isn't actually a 12V charging unit? What I like about them is that they are relatively inexpensive £50-100 and are portable so they can be stored onboard easily and in the event you find yourself unable to start the car.

I know there some long term EV owners on here and also technical wizards so I am sure the answer is out there.......

As an example I was thinking this one:

Arteck 800A Peak Portable Car Jump Starter (Up to 6.0L Gas or 4.0L Diesel Engine) QDSP Auto 12V Battery Pack Booster and QC3.0 External Battery Charger for Automotive, Motorcycle, Boat, Smart Phone: Amazon.co.uk: Car & Motorbike
 

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I don't think it's necessary but it sure will help in 12v vampire state.

If you go for a 12v booster select a one with LiFePO4 cells as these are much safer when it comes to fire and storage.

 

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You only really need this if you car is dormant for a month or more at a time.

Weekly use of a car should keep your 12V fine.

The only thing I'd like to know for 100% is how the Polestar 2 charges the 12v Battery.
When on AC charge?
When on DC charger?
When Driving?
The HV Battery can just charge the 12v when low?
A Mix of the above?

I know some people have speculated on how this works, but I don't remember seeing an official response from Polestar.
 

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The HV can only charge the 12v. Think the HV as a alternator in a ICE world. It charges as soon as in ignition mode from the 400v. It will also charge after a drive cycle, that's one of the reasons why the fan is running after lock.
 

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The HV can only charge the 12v. Think the HV as a alternator in a ICE world. It charges as soon as in ignition mode from the 400v. It will also charge after a drive cycle, that's one of the reasons why the fan is running after lock.
Can you explain what you mean here? There's no way there will be enough heat generated in charging the 12V battery to explain loud fans coming on.

When the car is fully powered up (i.e. the 400V battery is on), a DC-DC convertor will feed the 12V system in the car from the 400V system, and at the same time charge up the 12V battery while it's at it. When the 400V battery is off, the 12V is charged up automatically whenever it gets low enough; there was a thread elsewhere on here where someone kind uploaded some pictures about it.

I think having one of the small jump-starter batteries is a really good idea, given that when things go awry, what always dies is the 12V battery at which point it needs jumpstarting to even get onto the back of the tow truck.

I have one for my Kona after 12V problems (most EVs have 12V problems...) and we have one in our Zoe. The Kona's one will move to the Polestar.
 

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The onboard 12v charger (feed from 400v) will activate fan while it's active. It's not much of a heating problem, more precaution when the state is 12v charge.

No it will not top up the 12v battery while it's sleeping.

The 12v system is handling all the logic, so when it's low the 400V contactors will not be activated.

I know there is discussion in the EV world about integrating the 12V into the 400V pack so it will always be able to provide 12V. But the 400V contactors must always be present to activet HV after all systems are checked.
 

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You're right that the 12V system needs to power up the 400V system in order for it to charge the 12V, I completely agree. There was more discussion in this thread:


Every now and again, the system must wake up, check the 12V status, and if necessary turn on the 400V pack to top up the 12V battery, otherwise it would simply go flat after a matter of days as the background load (a.k.a. vampire drain) on the 12V battery is simply too high. This is what all Hyundai and Kia models do, for instance.

I'm still not sure I quite agree with what you say about the onboard charger turning the fans on, as the fans only seem to come on for maybe a minute or two, which is nowhere near long enough to properly charge up the 12V battery.
 

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Discussion Starter #8
I think having one of the small jump-starter batteries is a really good idea, given that when things go awry, what always dies is the 12V battery at which point it needs jumpstarting to even get onto the back of the tow truck.

I have one for my Kona after 12V problems (most EVs have 12V problems...) and we have one in our Zoe. The Kona's one will move to the Polestar.
Thanks for the feedback on this issue gents. However the system works I see too many issues of the 12v battery going flat. There was a recent YouTube video of an ID3 owner having real issues and it convinced me I needed a back up plan. @rgledhill I will certainly take the advice of a portable power booster, if nothing else just to get the car to a safe location and activate the tow mode.

just another thing to buy before the car lands. At least it keeps my mind busy whilst I wait! 😂
 

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Any ideas why EVs have more backgroung load (or vampire drain) than ICE cars? I can leave my normal cars for days (or even weeks if I leave it during holidays) and I never got a 12v battery flat. So I wonder why EVs would need more current to stay still than normal cars?
 

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My Ioniq used to top up the 12v overnight and most mornings displayed a message to that effect. Did you Kona do this @rgledhill ?
Yes, but if you went on lots of short journeys with the climate control on etc, it wouldn't put enough on overnight to make up for the heavy load during the journeys. So bit by bit, day by day, it would get flatter and flatter, until finally it just wouldn't start up properly.
This has now been fixed and it tops up the 12V battery every 4 hours instead of every 24 hours.

Sadly they still haven't fixed the sudden flattening of the battery that seems linked to one of the ECUs not shutting down properly!
 
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Any ideas why EVs have more backgroung load (or vampire drain) than ICE cars? I can leave my normal cars for days (or even weeks if I leave it during holidays) and I never got a 12v battery flat. So I wonder why EVs would need more current to stay still than normal cars?
They don't. They have the mostly the same as any ICE car. Problem is two fold.

Firstly some cars had additional drain like the Kona boot not shutting so it spends they whole time trying to close it overnight. Or like the Polestar where the monitoring software wasn't working correctly ... and it just spent 1 week in a dockyard, 4 weeks on a boat, 2-3 weeks finding it's way to you .... by the time it go there, it was already knackered ... then when the car doesn't charge it back up correctly, that's a problem.

The second problem is more a general EV issue. The 12v Battery has been developed over the past 50+ to to work in an ICE car. I likes the big pull of power at start up ... it then likes the gentle massage of the alternator trickling all over it. It's been designed to sit there for 2-4 weeks, give a big burst them get charged nice and slowly again to full.

In an EV it sits there doing boring old little Tasks ... like the Alarm, keyless entry, etc.. there is nothing there to require a good pull of power. So they decay a lot faster because they are not being used as designed.

Also newer cars have more tech while the car isn't running, so again more slow and minor drain.


In time the 12v will either be replaced or imho they will be one designed for EV's usage.
 

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Good summary! Yes, the constant low current drain causes the electrodes to "furr up", for want of a better word. The Kona actually has a Calcium battery in it which is supposed to deal with this better, but it doesn't seem to make any difference :rolleyes: .
 

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Thanks for the recommendation. I have one on order. I have only had one Propulsion System error. This was after the car had not been used for 5 days. After a quick trip along the M25 it disappeared and has not happened again. The car is back to daily use at the moment. Polestar support did say that the software update will fix the drain issue. A few time when standing by the car i hear the fans kick in randomly. It appears that a few manufacturers are fitting the lightest batteries they can. VW have been caught out with 12v battery issues as well as many others.
 

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ok,
They don't. They have the mostly the same as any ICE car. Problem is two fold.

Firstly some cars had additional drain like the Kona boot not shutting so it spends they whole time trying to close it overnight. Or like the Polestar where the monitoring software wasn't working correctly ... and it just spent 1 week in a dockyard, 4 weeks on a boat, 2-3 weeks finding it's way to you .... by the time it go there, it was already knackered ... then when the car doesn't charge it back up correctly, that's a problem.

The second problem is more a general EV issue. The 12v Battery has been developed over the past 50+ to to work in an ICE car. I likes the big pull of power at start up ... it then likes the gentle massage of the alternator trickling all over it. It's been designed to sit there for 2-4 weeks, give a big burst them get charged nice and slowly again to full.

In an EV it sits there doing boring old little Tasks ... like the Alarm, keyless entry, etc.. there is nothing there to require a good pull of power. So they decay a lot faster because they are not being used as designed.

Also newer cars have more tech while the car isn't running, so again more slow and minor drain.


In time the 12v will either be replaced or imho they will be one designed for EV's usage.
Thanks a lot! There are then some differences due to the way ICE and EV works, interesting!
 

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With the Kona or Polestar? My Kona flattened its 12V battery again over the weekend...

For the Polestar, it does seem like more recently it's cars that have other failures (e.g. battery temperature sensor or inverter) that have then had their 12V battery go flat due to the fans going into hurricane mode, so hopefully there shouldn't be any more genuine 12V gradual flattening problems.
 

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To get to the 12V battery terminals you have to take a cover off under the front boot, on the right as you look at the car.
I don't know whether you could connect the booster via the 12v socket in the boot which would be the easiest.
Perhaps someone who is more techy could help.
I have a booster for other ICE cars which works well but never tried it on the P2
 
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