12v Battery: Not an afterthought

[Logan]

Random thought (prompted by @Scoutsie ).

Sadly, the 12v battery is something of an afterthought for many EV's. Often leading to them being buried somewhere random/hard to access. And it failing can often be a big pain in the butt. You often can't even get into the vehicle, it might not drive (even though the high voltage battery is charged), or other pretty major disruptions there.

For instance, on the updated Rivian R1 series, the 12v battery is... under the front passenger seat (requires removal of the passenger seat to access). That seems... suboptimal.

I'd love for the 12v battery to be more than an afterthought for the Scout. I'm not sure how it would be best handled, and I'm fine leaving that to the Scout Engineers.

Some random ideas/thoughts:

• If we could gain access to the frunk with a physical key, and if the 12v battery was somewhere under a panel in the frunk, that would be great (easy to get to/replace).
• If part of the high voltage battery is segmented off and acts as the 12v battery?

All in all, its a relatively minor thing. But its a quality of life thing for longer term owners, and people that find themselves off the beaten path more often, which means its something thats on my mind.

 

[Crazychicken563]

Reviving an old thread to comment on a 12v battery issue I'm going through right now, and how important it is for Scout to get this right.

First off, I absolutely agree that it has to be easily accessible in order to "jump" the car. There are so many things that rely on the 12v working, and in my case the DC to DC converter that keeps the 12v topped off failed. The difference between having a brick I needed towed vs a car I could limp to a service center was accessibility to the 12v battery. This is particularly important for those of us who may be taking the car far off the beaten path.

On the note of the DC to DC converter - another major issue I have with my EV is that the 12v battery is ONLY charged while the vehicle is on (being driven). If the car sits for a week in the winter cold, the 12v will just slowly die. Personally I think this is just a lazy carryover from the behavior that ICE cars have. There's no reason why an EV couldn't "wake up" once a day or so to check the voltage of the 12v battery and top it off from the main battery if necessary. Zero reason to wait for someone to actually be driving the car in order to have that charging circuit working.

 

[BeerParty]

Reviving an old thread to comment on a 12v battery issue I'm going through right now, and how important it is for Scout to get this right.

First off, I absolutely agree that it has to be easily accessible in order to "jump" the car. There are so many things that rely on the 12v working, and in my case the DC to DC converter that keeps the 12v topped off failed. The difference between having a brick I needed towed vs a car I could limp to a service center was accessibility to the 12v battery. This is particularly important for those of us who may be taking the car far off the beaten path.

On the note of the DC to DC converter - another major issue I have with my EV is that the 12v battery is ONLY charged while the vehicle is on (being driven). If the car sits for a week in the winter cold, the 12v will just slowly die. Personally I think this is just a lazy carryover from the behavior that ICE cars have. There's no reason why an EV couldn't "wake up" once a day or so to check the voltage of the 12v battery and top it off from the main battery if necessary. Zero reason to wait for someone to actually be driving the car in order to have that charging circuit working.

Would you be willing to share what EV you have that doesn't charge the 12V when the vehicle is not powered on? It never occurred to me that there might be an EV that only charges the 12V battery when the vehicle is powered on. That seems like a really terrible design.

My Hyundai Ioniq 5 has an LED on the dash that lights up when the 12V is being charged and the car is powered off. This quirk has led to many questions/discussions in the HI5 forums. I always wondered when Hyundai would include an indicator for this, it seemed silly to "announce" that the car was charging the 12V battery. But if this isn't a standard thing, maybe they felt they needed to have an indicator.

 

[Crazychicken563]

Would you be willing to share what EV you have that doesn't charge the 12V when the vehicle is not powered on? It never occurred to me that there might be an EV that only charges the 12V battery when the vehicle is powered on. That seems like a really terrible design.

My Hyundai Ioniq 5 has an LED on the dash that lights up when the 12V is being charged and the car is powered off. This quirk has led to many questions/discussions in the HI5 forums. I always wondered when Hyundai would include an indicator for this, it seemed silly to "announce" that the car was charging the 12V battery. But if this isn't a standard thing, maybe they felt they needed to have an indicator.

I have a Launch Edition 2021 Polestar 2.

It was their first EV and they've certainly worked out quite a few quirks since the early days. Def agree it's an awful oversight - hence my comment here about it. Presumably it's an easy mistake to make for a new company given what I'm dealing with.

I think an indicator for the battery charging is great - I much prefer to have a readout than to deal with a system that tells me nothing and I have to silently assume it all works. But then again my ICE car is a WRX with a mountain of gauges so might just be a me thing..

 

[Logan]

Would you be willing to share what EV you have that doesn't charge the 12V when the vehicle is not powered on? It never occurred to me that there might be an EV that only charges the 12V battery when the vehicle is powered on. That seems like a really terrible design.

My Hyundai Ioniq 5 has an LED on the dash that lights up when the 12V is being charged and the car is powered off. This quirk has led to many questions/discussions in the HI5 forums. I always wondered when Hyundai would include an indicator for this, it seemed silly to "announce" that the car was charging the 12V battery. But if this isn't a standard thing, maybe they felt they needed to have an indicator.

Strangely, they removed that indicator on more recent models, and my Ioniq 9 doesn't have that same feature.

I have a Launch Edition 2021 Polestar 2.

It was their first EV and they've certainly worked out quite a few quirks since the early days. Def agree it's an awful oversight - hence my comment here about it. Presumably it's an easy mistake to make for a new company given what I'm dealing with.

I think an indicator for the battery charging is great - I much prefer to have a readout than to deal with a system that tells me nothing and I have to silently assume it all works. But then again my ICE car is a WRX with a mountain of gauges so might just be a me thing..

I really hope that the 12v battery is one that will be charged while the vehicle is off. And that it is something that I can figure out without being locked out of (or into) the vehicle.

IE, if I come back from a backpacking trip, and want to get into my car, but the 12v battery is dead, I want to be able to get into the car without disassembling it (looking at you Tesla), get my 12v battery booster/jumpstarter thing out from the glovebox, pop the frunk, and "jump" the thing enough to turn it on, and get me home.

 

[cyure]

Strangely, they removed that indicator on more recent models, and my Ioniq 9 doesn't have that same feature.



I really hope that the 12v battery is one that will be charged while the vehicle is off. And that it is something that I can figure out without being locked out of (or into) the vehicle.

IE, if I come back from a backpacking trip, and want to get into my car, but the 12v battery is dead, I want to be able to get into the car without disassembling it (looking at you Tesla), get my 12v battery booster/jumpstarter thing out from the glovebox, pop the frunk, and "jump" the thing enough to turn it on, and get me home.

Since the door handles on the Scout are mechanical wouldn’t they be like any other ICE car and you can just unlock the door and open it?

 

[Logan]

Since the door handles on the Scout are mechanical wouldn’t they be like any other ICE car and you can just unlock the door and open it?

One of the reasons I'm interested in it. And why I want something that has a physical key .

But yes, the "getting into the vehicle" part is greatly assisted by the "ability to open the doors". Something that electric door handles struggle to do, without electricity.

The next part is just making it easy to find a place to jump the battery/replace the 12v battery. I don't want to have to take my scout to a service center, because the 12v battery is underneath the passenger seat (looking at you Rivian :/).

I'm hopeful here. But made the request public just so scout could see what we wanted .

 

[Crazychicken563]

I'm certainly very curious how Scout is going to manage packaging the 12v battery along with the harvester while maintaining a large frunk. Presumably the harvester has an alternator? Or maybe not? Curious how that will dictate packaging, but we can only wait and see.. This all ties into how easy it is to work on the car in general for at home maintenance and such, but I don't want to derail the main discussion of this thread.

Let us get to the 12v easily ty!

 

[strider]

Some random ideas/thoughts:

• If we could gain access to the frunk with a physical key, and if the 12v battery was somewhere under a panel in the frunk, that would be great (easy to get to/replace).
• If part of the high voltage battery is segmented off and acts as the 12v battery?

Tesla did the second one with the original Roadster. It ended up causing problems with premature degredation of those cells and difficulty keeping the overall pack balanced. When I bought my v2.5 Roadster in 2010 they had added a 12V motorcycle battery in front of the right front wheel and stopped segmenting the HV battery.

Tesla has gone 16V but only because they got sick of buying 12V batteries from Interestate and made their own from LiIon cells. But based on the cell math they ended up at 16V. Caused some drama for people that wanted to use cigarette lighter powered devices that couldn't handle 16V like tire pumps, radar detectors, etc.

LV battery death is fairly rare. The car will alert you when the battery is getting low. With a Tesla you do need to "jump" the car with 12V in order to open the frunk but once you're in there you can get to the battery (or continue to "jump" the car to close the HV contactors and then you can drive).

 

[BeerParty]

Presumably the harvester has an alternator?

Yes, the Harvester has an alternator. After all, generating electrical power is the whole point of the Harvester.

An alternator is for generating electrical power from a running engine. In an typical ICE vehicle the engine mainly drives the wheels, but it also drives an alternator to provide 12V power for the car and to charge the 12V battery. The Harvester in the Scout runs specifically to add power to the traction battery, so in a sense it is only for driving an alternator.

 

[Crazychicken563]

Yes, the Harvester has an alternator. After all, generating electrical power is the whole point of the Harvester.

An alternator is for generating electrical power from a running engine. In an typical ICE vehicle the engine mainly drives the wheels, but it also drives an alternator to provide 12V power for the car and to charge the 12V battery. The Harvester in the Scout runs specifically to add power to the traction battery, so in a sense it is only for driving an alternator.

Well. I know it will drive a bigole generator for the bigole main battery. I was talking about it also having a traditional 14v alternator to charge the 12v alongside that.

In theory they could get away with having the harvester just charge the main battery and then the main battery charges the 12v through a DC to DC stepdown circuit. Then there's no traditional alternator in play.

Would also result in fewer (or zero?) belts to replace for maintenance.