[eqvinox]

They do (I've seen photos of assistance service cars with a bunch of batteries tacked on in the back), but it's a very new thing and not very common yet.

Also the assistance service cars are mostly petrol based still, but even for electric ones I've been told it's non-trivial to wire the existing batteries out (… safety mechanisms and whatnot), making extra battery packs the go-to.

[krisoft]

> making extra battery packs the go-to

I mean we are not talking about charging the vehicle to full. You only need like a hand portable battery to jump start the low voltage system.

The procedure is described in the owner's manual: "In the unlikely event that Model 3 loses electrical power, you cannot access the touchscreen and are therefore unable to release the parking brake without first jump starting (see Jump Starting)."[1]

And the jump starting procedure is described here: https://www.tesla.com/ownersmanual/model3/en_au/GUID-3567D5F...

1: https://www.tesla.com/ownersmanual/model3/en_au/GUID-3DFFB07...

[eqvinox]

Jump starting might've helped in this specific scenario, but I'd assume there are other scenarios where you need a minute or two of electrical power in the vehicle, maybe to move itself out some stupid situation or get it un-stuck…

[cj]

Slightly ironic that the jumpstart instructions differ depending on the type of battery. And the way to determine which type of battery you have is by using the touchscreen (which of course wouldn’t work if your battery is dead)