The problem with Tesla cars is that they uses two batteries.

Every single electric car has a low voltage system. Every single one. With maybe the exception of the G-Wiz.

You don't want hundreds of volts flowing through your lights etc. and you don't want an inverter running 24/7 in case you want to remote unlock your car.

One is the main one, which is used for propulsion, and the other one, a conventional car battery, is used for most of the critical electronic

Newer Teslas have a 16 volt lithium battery for the low voltage stuff. In theory it's more resilient to low charge conditions. Video here if you're interested: https://youtu.be/8-MNFgashpQ

Problem is, both are independent from each other, which mean you can have a full main battery, and still be locked out of your car if the secondary on is out. And those batteries hate cold.

The car is more than capable of topping up the low voltage battery from the high voltage battery should it be required, and in fact they do this if they are sitting for a while. I have left my Tesla for a couple of weeks without moving it without issue. Including in the cold. Although James May did have an issue with his model 3 during lockdown if I remember correctly.

Hyundai cars are notorious for allowing the low voltage system to run low, but I believe firmware updates have resolved that.

You can have a similar results with gas car, where the ignition won't happen because of the cold, but at least you can recharge it easily with another car that happens to pass by. For Teslas, you can't. Because those fuckers decided that it was too unsightly to see the bare battery, and bolted a plastic turd over it to make sure the only person to ever be able to change it is a Tesla tech.

It's a five minute job to remove that cover. Really. The plastic cover is a non issue.

All other car manufacturers, which happens to have a bit more experience than those asses, understood that being able to have an unified battery, that happens to be thermally insulated (and often in the nordic countries, heated), to make sure you actually use them, even in cold weather.

I'm intrigued. Please give me examples of this.

Tesla cars are a perfect example of a product that only survive out of hype.

If you don't like them, you don't like them. That's fine. Nobody has a gun to your head. But you probably shouldn't be making up stuff for no reason.